diff --git a/src/test/kotlin/dev/usbharu/hideout/activitypub/interfaces/api/webfinger/WebFingerControllerTest.kt b/src/test/kotlin/dev/usbharu/hideout/activitypub/interfaces/api/webfinger/WebFingerControllerTest.kt
new file mode 100644
index 00000000..41017444
--- /dev/null
+++ b/src/test/kotlin/dev/usbharu/hideout/activitypub/interfaces/api/webfinger/WebFingerControllerTest.kt
@@ -0,0 +1,100 @@
+package dev.usbharu.hideout.activitypub.interfaces.api.webfinger
+
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import dev.usbharu.hideout.activitypub.domain.model.webfinger.WebFinger
+import dev.usbharu.hideout.activitypub.service.webfinger.WebFingerApiService
+import dev.usbharu.hideout.application.config.ApplicationConfig
+import dev.usbharu.hideout.core.domain.exception.FailedToGetResourcesException
+import kotlinx.coroutines.test.runTest
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.mockito.InjectMocks
+import org.mockito.Mock
+import org.mockito.junit.jupiter.MockitoExtension
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.doThrow
+import org.mockito.kotlin.eq
+import org.mockito.kotlin.whenever
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get
+import org.springframework.test.web.servlet.result.MockMvcResultHandlers.print
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers.status
+import org.springframework.test.web.servlet.setup.MockMvcBuilders
+import utils.UserBuilder
+
+@ExtendWith(MockitoExtension::class)
+class WebFingerControllerTest {
+
+    private lateinit var mockMvc: MockMvc
+
+    @Mock
+    private lateinit var webFingerApiService: WebFingerApiService
+
+    @Mock
+    private lateinit var applicationConfig: ApplicationConfig
+
+    @InjectMocks
+    private lateinit var webFingerController: WebFingerController
+
+    @BeforeEach
+    fun setUp() {
+        this.mockMvc = MockMvcBuilders.standaloneSetup(webFingerController).build()
+    }
+
+    @Test
+    fun `webfinger 存在するacctを指定したとき200 OKでWebFingerのレスポンスが返ってくる`() = runTest {
+
+        val user = UserBuilder.localUserOf()
+        whenever(
+            webFingerApiService.findByNameAndDomain(
+                eq("hoge"),
+                eq("example.com")
+            )
+        ).doReturn(user)
+
+        val contentAsString = mockMvc.perform(get("/.well-known/webfinger?resource=acct:hoge@example.com"))
+            .andDo(print())
+            .andExpect(status().isOk())
+            .andReturn()
+            .response
+            .contentAsString
+
+        val objectMapper = jacksonObjectMapper()
+
+        val readValue = objectMapper.readValue<WebFinger>(contentAsString)
+
+        val expected = WebFinger(
+            subject = "acct:${user.name}@${user.domain}",
+            listOf(
+                WebFinger.Link(
+                    "self",
+                    "application/activity+json",
+                    user.url
+                )
+            )
+        )
+
+        assertThat(readValue).isEqualTo(expected)
+    }
+
+    @Test
+    fun `webfinger 存在しないacctを指定したとき404 Not Foundが返ってくる`() = runTest {
+        whenever(webFingerApiService.findByNameAndDomain(eq("fuga"), eq("example.com"))).doThrow(
+            FailedToGetResourcesException::class
+        )
+
+        mockMvc.perform(get("/.well-known/webfinger?resource=acct:fuga@example.com"))
+            .andDo(print())
+            .andExpect(status().isNotFound)
+    }
+
+    @Test
+    fun `webfinger acctとして解釈できない場合は400 Bad Requestが返ってくる`() {
+        mockMvc.perform(get("/.well-known/webfinger?resource=@hello@aa@aab@aaa"))
+            .andDo(print())
+            .andExpect(status().isBadRequest)
+    }
+}