diff --git a/library/src/commonMain/kotlin/dev/usbharu/markdown/Lexer.kt b/library/src/commonMain/kotlin/dev/usbharu/markdown/Lexer.kt
index d0d0aeb..8887aae 100644
--- a/library/src/commonMain/kotlin/dev/usbharu/markdown/Lexer.kt
+++ b/library/src/commonMain/kotlin/dev/usbharu/markdown/Lexer.kt
@@ -10,6 +10,7 @@ class Lexer {
         var inQuote = false //引用中の判断
         var inCode = false //コードブロック内の判断
         var inline = false //行頭の判断
+        var htmlNest = 0
         val codeBuffer = StringBuilder()
 
         line@ while (lines.hasNext()) {
@@ -26,9 +27,11 @@ class Lexer {
                             inCode = codeblock(iterator, next, tokens, inCode, codeBuffer, inline)
                         }
 
-                        inCode -> {
-                            codeBuffer.append(next)
-                        }
+                        inCode -> codeBuffer.append(next)
+
+                        next == '<' -> htmlNest = html(iterator, htmlNest, codeBuffer, tokens, next)
+
+                        htmlNest != 0 -> codeBuffer.append(next)
 
                         (next == '#' || next == '＃') && !inline -> header(iterator, tokens)
                         (next == '>' || next == '＞') && !inQuote && !inline -> {
@@ -80,6 +83,8 @@ class Lexer {
 
                 if (inCode) {
                     codeBuffer.append("\n")
+                } else if (htmlNest != 0) {
+                    codeBuffer.append(" ")
                 } else {
                     tokens.add(Break(1))
                 }
@@ -98,6 +103,95 @@ class Lexer {
         return tokens
     }
 
+    private fun html(
+        iterator: PeekableCharIterator,
+        htmlNest: Int,
+        codeBuffer: StringBuilder,
+        tokens: MutableList<Token>,
+        next: Char
+    ): Int {
+        var htmlNest1 = htmlNest
+        var endTag = false
+        var counter = 0
+        if (iterator.peekOrNull() == '/') {
+            endTag = true
+            counter++
+        }
+        val tagNameBuilder = StringBuilder()
+        counter = skipPeekWhitespace(iterator, counter)
+
+        while (iterator.peekOrNull(counter) != null &&
+            iterator.peekOrNull(counter)?.isWhitespace() != true &&
+            iterator.peekOrNull(counter) != '>' &&
+            iterator.peekOrNull(counter) != '/'
+        ) {
+            tagNameBuilder.append(iterator.peekOrNull(counter))
+            counter++
+        }
+
+        counter = skipPeekWhitespace(iterator, counter)
+        val attributeList = mutableListOf<Token>()
+        intag@ while (iterator.peekOrNull(counter) != null &&
+            (iterator.peekOrNull(counter) != '/' && iterator.peekOrNull(counter) != '>')
+        ) {
+            val attrBuilder = StringBuilder()
+            attr@ while (iterator.peekOrNull(counter) != null && (iterator.peekOrNull(counter) != '=' && iterator.peekOrNull(
+                    counter
+                )?.isWhitespace() != true)
+            ) {
+                attrBuilder.append(iterator.peekOrNull(counter))
+                counter++
+            }
+            attributeList.add(AttributeName(attrBuilder.toString()))
+            counter = skipPeekWhitespace(iterator, counter)
+            if (iterator.peekOrNull(counter) == '=') {
+                counter++
+                if (iterator.peekOrNull(counter) == '"') {
+                    counter++
+                    //todo エスケープシーケンス
+                    val peekString = offsetPeekString(iterator, counter, '"')
+                    counter = peekString?.second?.minus(1) ?: counter
+                    if (peekString != null) {
+                        attributeList.add(AttributeValue(peekString.first))
+                    } else {
+                        break@intag
+                    }
+                }
+            }
+            counter++
+            counter = skipPeekWhitespace(iterator, counter)
+        }
+
+        val void = if (iterator.peekOrNull(counter) == '/') {//閉じタグ省略
+            counter = skipPeekWhitespace(iterator, counter)
+            val peekString = offsetPeekString(iterator, counter, '>')
+            counter = peekString?.second?.minus(1) ?: counter
+            htmlNest1-- //あとで1増えるので相殺するためにあらかじめ1減らしておく
+            true
+        } else {
+            false
+        }
+        if (iterator.peekOrNull(counter) == '>') { //タグか判定
+            if (codeBuffer.isNotBlank()) { //タグ間に文字があれば追加する
+                tokens.add(HtmlValue(codeBuffer.toString().trim()))
+                codeBuffer.clear()
+            }
+            if (endTag) {//閉じタグ判定
+                htmlNest1-- //閉じタグならネストを一つ減らす
+                tokens.add(EndTagStart(tagNameBuilder.toString()))
+            } else {
+                htmlNest1++
+                tokens.add(StartTagStart(tagNameBuilder.toString(), void))
+            }
+            tokens.addAll(attributeList)
+            tokens.add(TagEnd(tagNameBuilder.toString()))
+            iterator.skip(counter + 1)
+        } else {
+            addText(tokens, next.toString())
+        }
+        return htmlNest1
+    }
+
     private fun strike(
         iterator: PeekableCharIterator,
         next: Char,
@@ -357,6 +451,34 @@ class Lexer {
         return count
     }
 
+    fun skipPeekWhitespace(iterator: PeekableCharIterator, currentOffset: Int = 0): Int {
+        var offset = currentOffset
+        while (iterator.peekOrNull(offset)?.isWhitespace() == true) {
+            offset++
+        }
+        return offset
+    }
+
+    fun offsetPeekString(iterator: PeekableCharIterator, offset: Int = 0, vararg chars: Char): Pair<String, Int>? {
+        var counter = offset
+        val stringBuilder = StringBuilder()
+        var checkCounter = 0
+        while (iterator.peekOrNull(counter) != null && checkCounter < chars.size) {
+            stringBuilder.append(iterator.peekOrNull(counter))
+            if (iterator.peekOrNull(counter) == chars[checkCounter]) {
+                checkCounter++
+            } else {
+                checkCounter = 0
+            }
+            counter++
+        }
+        if (iterator.peekOrNull(counter) == null && checkCounter != chars.size) {
+            return null
+        }
+        val string = stringBuilder.toString()
+        return string.substring(0, string.length - chars.size) to counter
+    }
+
     fun peekString(iterator: PeekableCharIterator, vararg char: Char): String? {
         var counter = 0
         val stringBuilder = StringBuilder()
diff --git a/library/src/commonMain/kotlin/dev/usbharu/markdown/Token.kt b/library/src/commonMain/kotlin/dev/usbharu/markdown/Token.kt
index 5a45610..fee0355 100644
--- a/library/src/commonMain/kotlin/dev/usbharu/markdown/Token.kt
+++ b/library/src/commonMain/kotlin/dev/usbharu/markdown/Token.kt
@@ -29,4 +29,12 @@ data class UrlTitle(val title: String) : Token()
 data class InlineCodeBlock(val text: String) : Token()
 data class CodeBlock(val text: String) : Token()
 data class CodeBlockLanguage(val language: String, val filename: String) : Token()
-data class Strike(val strike: String) : Token()
\ No newline at end of file
+data class Strike(val strike: String) : Token()
+
+abstract class Html() : Token()
+data class StartTagStart(var tag: String, val void: Boolean) : Html()
+data class EndTagStart(var tag: String) : Html()
+data class TagEnd(var tag: String) : Html()
+data class AttributeName(val name: String) : Html()
+data class AttributeValue(val value: String) : Html()
+data class HtmlValue(val value: String) : Html()
\ No newline at end of file
diff --git a/library/src/commonTest/kotlin/dev/usbharu/markdown/LexerTest.kt b/library/src/commonTest/kotlin/dev/usbharu/markdown/LexerTest.kt
index bc02762..8f12903 100644
--- a/library/src/commonTest/kotlin/dev/usbharu/markdown/LexerTest.kt
+++ b/library/src/commonTest/kotlin/dev/usbharu/markdown/LexerTest.kt
@@ -342,8 +342,7 @@ class LexerTest {
         println(actual)
 
         assertContentEquals(
-            listOf(DiscList, Text("aiueo"), Break(1), Whitespace(4, ' '), DiscList, Text("abcd")),
-            actual
+            listOf(DiscList, Text("aiueo"), Break(1), Whitespace(4, ' '), DiscList, Text("abcd")), actual
         )
     }
 
@@ -357,14 +356,8 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                DecimalList('1'),
-                Text("aiueo"),
-                Break(1),
-                Whitespace(4, ' '),
-                DecimalList('2'),
-                Text("abcd")
-            ),
-            actual
+                DecimalList('1'), Text("aiueo"), Break(1), Whitespace(4, ' '), DecimalList('2'), Text("abcd")
+            ), actual
         )
     }
 
@@ -378,14 +371,8 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                DecimalList('１'),
-                Text("aiueo"),
-                Break(1),
-                Whitespace(4, ' '),
-                DecimalList('２'),
-                Text("abcd")
-            ),
-            actual
+                DecimalList('１'), Text("aiueo"), Break(1), Whitespace(4, ' '), DecimalList('２'), Text("abcd")
+            ), actual
         )
     }
 
@@ -399,14 +386,8 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                DecimalList('1'),
-                Text("aiueo"),
-                Break(1),
-                Whitespace(4, ' '),
-                DecimalList('2'),
-                Text("abcd")
-            ),
-            actual
+                DecimalList('1'), Text("aiueo"), Break(1), Whitespace(4, ' '), DecimalList('2'), Text("abcd")
+            ), actual
         )
     }
 
@@ -446,11 +427,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Text("こんにちは～"),
-                Whitespace(1, ' '),
-                Url("https://example.com"),
-                Break(1),
-                Text("あいうえお")
+                Text("こんにちは～"), Whitespace(1, ' '), Url("https://example.com"), Break(1), Text("あいうえお")
             ), actual
         )
     }
@@ -495,9 +472,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Asterisk(1, '*'),
-                Text("a"),
-                Asterisk(1, '*')
+                Asterisk(1, '*'), Text("a"), Asterisk(1, '*')
             ), actual
         )
     }
@@ -512,10 +487,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Quote(1),
-                Asterisk(1, '*'),
-                Text("a"),
-                Asterisk(1, '*')
+                Quote(1), Asterisk(1, '*'), Text("a"), Asterisk(1, '*')
             ), actual
         )
     }
@@ -530,9 +502,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Asterisk(2, '*'),
-                Text("a"),
-                Asterisk(2, '*')
+                Asterisk(2, '*'), Text("a"), Asterisk(2, '*')
             ), actual
         )
     }
@@ -547,9 +517,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Asterisk(2, '_'),
-                Text("a"),
-                Asterisk(2, '_')
+                Asterisk(2, '_'), Text("a"), Asterisk(2, '_')
             ), actual
         )
     }
@@ -817,12 +785,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Text("aiueo"),
-                Whitespace(1, ' '),
-                Text("```abcd"),
-                Asterisk(1, '*'),
-                Text("a"),
-                Asterisk(1, '*')
+                Text("aiueo"), Whitespace(1, ' '), Text("```abcd"), Asterisk(1, '*'), Text("a"), Asterisk(1, '*')
             ), actual
         )
     }
@@ -863,10 +826,7 @@ class LexerTest {
 
         assertContentEquals(
             listOf(
-                Text("aiueo"),
-                Whitespace(1, ' '),
-                Strike("aiueo"),
-                Text("bcde")
+                Text("aiueo"), Whitespace(1, ' '), Strike("aiueo"), Text("bcde")
             ), actual
         )
     }
@@ -900,4 +860,265 @@ class LexerTest {
             ), actual
         )
     }
+
+    @Test
+    fun html() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\">")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false), AttributeName("attr"), AttributeValue("value"), TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html2() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false), TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html閉じタグ() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\"></tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                TagEnd("tagName"),
+                EndTagStart("tagName"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html内容() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\">hello</tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                TagEnd("tagName"),
+                HtmlValue("hello"),
+                EndTagStart("tagName"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun htmlネスト() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\"><tagB>hello</tagB></tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                TagEnd("tagName"),
+                StartTagStart("tagB", false),
+                TagEnd("tagB"),
+                HtmlValue("hello"),
+                EndTagStart("tagB"),
+                TagEnd("tagB"),
+                EndTagStart("tagName"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun htmlかと思ったら違った() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\"")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                Text("<tagName"), Whitespace(1, ' '), Text("attr=\"value\"")
+            ), actual
+        )
+    }
+
+    @Test
+    fun htmlのアトリビュートかと思ったら違った() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                Text("<tagName"), Whitespace(1, ' '), Text("attr=\"value>")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html複数行() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\">\nvalue\n</tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                TagEnd("tagName"),
+                HtmlValue("value"),
+                EndTagStart("tagName"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html改行() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\">\nvalue\nfaaaa</tagName>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                TagEnd("tagName"),
+                HtmlValue("value faaaa"),
+                EndTagStart("tagName"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun htmlアトリビュートいっぱい() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName attr=\"value\" attr2=\"aaaaaaa\">")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", false),
+                AttributeName("attr"),
+                AttributeValue("value"),
+                AttributeName("attr2"),
+                AttributeValue("aaaaaaa"),
+                TagEnd("tagName")
+            ), actual
+        )
+    }
+
+    @Test
+    fun `html騙し続ける`() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<<<<<<")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                Text("<<<<<<")
+            ), actual
+        )
+    }
+
+    @Test
+    fun html閉じタグ省略() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<tagName/>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("tagName", true),
+                TagEnd("tagName"),
+
+                ), actual
+        )
+    }
+
+    @Test
+    fun html閉じタグ省略ネスト() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<b><a/></b>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("b", false),
+                TagEnd("b"),
+                StartTagStart("a", true),
+                TagEnd("a"),
+                EndTagStart("b"),
+                TagEnd("b"),
+            ), actual
+        )
+    }
+
+    @Test
+    fun html閉じタグ省略ネストと内容() {
+        val lexer = Lexer()
+
+        val actual = lexer.lex("<b><a/>aaaa</b>")
+
+        println(actual)
+
+        assertContentEquals(
+            listOf(
+                StartTagStart("b", false),
+                TagEnd("b"),
+                StartTagStart("a", true),
+                TagEnd("a"),
+                HtmlValue("aaaa"),
+                EndTagStart("b"),
+                TagEnd("b"),
+            ), actual
+        )
+    }
 }
\ No newline at end of file