diff --git a/__tests__/comment.test.ts b/__tests__/comment.test.ts
index 7b926b1..3d7146c 100644
--- a/__tests__/comment.test.ts
+++ b/__tests__/comment.test.ts
@@ -5,6 +5,7 @@ import {
   createComment,
   deleteComment,
   findPreviousComment,
+  getBodyOf,
   updateComment
 } from "../src/comment"
 
@@ -177,3 +178,42 @@ it("deleteComment", async () => {
     repo: "sticky-pull-request-comment"
   })
 })
+
+describe("getBodyOf", () => {
+  const nullPrevious = {}
+  const simplePrevious = {
+    body: "hello there\n<!-- Sticky Pull Request CommentTypeA -->"
+  }
+  const detailsPrevious = {
+    body: `
+    <details open>
+    <summary>title</summary>
+
+    content
+    </details>
+    <!-- Sticky Pull Request CommentTypeA -->
+  `
+  }
+  const replaced = `
+    <details>
+    <summary>title</summary>
+
+    content
+    </details>
+    <!-- Sticky Pull Request CommentTypeA -->
+  `
+  test.each`
+    append   | hideDetails | previous           | expected
+    ${false} | ${false}    | ${detailsPrevious} | ${undefined}
+    ${true}  | ${false}    | ${nullPrevious}    | ${undefined}
+    ${true}  | ${false}    | ${detailsPrevious} | ${detailsPrevious.body}
+    ${true}  | ${true}     | ${nullPrevious}    | ${undefined}
+    ${true}  | ${true}     | ${simplePrevious}  | ${simplePrevious.body}
+    ${true}  | ${true}     | ${detailsPrevious} | ${replaced}
+  `(
+    "receive $previous, $append, $hideDetails and returns $expected",
+    ({append, hideDetails, previous, expected}) => {
+      expect(getBodyOf(previous, append, hideDetails)).toEqual(expected)
+    }
+  )
+})
diff --git a/__tests__/config.test.ts b/__tests__/config.test.ts
index c928ed1..20943f7 100644
--- a/__tests__/config.test.ts
+++ b/__tests__/config.test.ts
@@ -4,6 +4,7 @@ beforeEach(() => {
   process.env["INPUT_APPEND"] = "false"
   process.env["INPUT_RECREATE"] = "false"
   process.env["INPUT_DELETE"] = "false"
+  process.env["INPUT_HIDE_DETAILS"] = "false"
   process.env["INPUT_GITHUB_TOKEN"] = "some-token"
 })
 
@@ -17,6 +18,7 @@ afterEach(() => {
   delete process.env["INPUT_APPEND"]
   delete process.env["INPUT_RECREATE"]
   delete process.env["INPUT_DELETE"]
+  delete process.env["INPUT_HIDE_DETAILS"]
   delete process.env["INPUT_GITHUB_TOKEN"]
   delete process.env["INPUT_PATH"]
 })
@@ -31,6 +33,7 @@ test("repo", () => {
     append: false,
     recreate: false,
     deleteOldComment: false,
+    hideDetails: false,
     githubToken: "some-token"
   })
 })
@@ -44,6 +47,7 @@ test("header", () => {
     append: false,
     recreate: false,
     deleteOldComment: false,
+    hideDetails: false,
     githubToken: "some-token"
   })
 })
@@ -57,6 +61,7 @@ test("append", () => {
     append: true,
     recreate: false,
     deleteOldComment: false,
+    hideDetails: false,
     githubToken: "some-token"
   })
 })
@@ -70,6 +75,7 @@ test("recreate", () => {
     append: false,
     recreate: true,
     deleteOldComment: false,
+    hideDetails: false,
     githubToken: "some-token"
   })
 })
@@ -83,6 +89,21 @@ test("delete", () => {
     append: false,
     recreate: false,
     deleteOldComment: true,
+    hideDetails: false,
+    githubToken: "some-token"
+  })
+})
+test("hideDetails", () => {
+  process.env["INPUT_HIDE_DETAILS"] = "true"
+  expect(require("../src/config")).toMatchObject({
+    pullRequestNumber: expect.any(Number),
+    repo: {owner: "marocchino", repo: "stick-pull-request-comment"},
+    body: "",
+    header: "",
+    append: false,
+    recreate: false,
+    deleteOldComment: false,
+    hideDetails: true,
     githubToken: "some-token"
   })
 })
@@ -97,6 +118,7 @@ describe("path", () => {
       append: false,
       recreate: false,
       deleteOldComment: false,
+      hideDetails: false,
       githubToken: "some-token"
     })
   })
@@ -111,6 +133,7 @@ describe("path", () => {
       append: false,
       recreate: false,
       deleteOldComment: false,
+      hideDetails: false,
       githubToken: "some-token"
     })
   })
@@ -126,6 +149,7 @@ test("message", () => {
     append: false,
     recreate: false,
     deleteOldComment: false,
+    hideDetails: false,
     githubToken: "some-token"
   })
 })
diff --git a/action.yml b/action.yml
index a9d927c..8e516a4 100644
--- a/action.yml
+++ b/action.yml
@@ -18,6 +18,10 @@ inputs:
     description: "delete the previously created comment. Only `true` is allowed. Just skip this item when you don't need it."
     default: "false"
     required: false
+  hide_details:
+    description: "hide summary tags in the previously created comment. Only `true` is allowed. Just skip this item when you don't need it."
+    default: "false"
+    required: false
   message:
     description: "comment message"
     required: false
diff --git a/src/comment.ts b/src/comment.ts
index b58fe07..862da94 100644
--- a/src/comment.ts
+++ b/src/comment.ts
@@ -81,3 +81,19 @@ export async function deleteComment(
     comment_id
   })
 }
+
+export function getBodyOf(
+  previous: {body?: string},
+  append: boolean,
+  hideDetails: boolean
+): string | undefined {
+  if (!append) {
+    return undefined
+  }
+
+  if (!hideDetails) {
+    return previous.body
+  }
+
+  return previous.body?.replace(/(<details.*?)\s*\bopen\b(.*>)/g, "$1$2")
+}
diff --git a/src/config.ts b/src/config.ts
index 5e2f9a0..acd0f6a 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -9,6 +9,9 @@ export const pullRequestNumber =
 export const repo = buildRepo()
 export const header = core.getInput("header", {required: false})
 export const append = core.getBooleanInput("append", {required: true})
+export const hideDetails = core.getBooleanInput("hide_details", {
+  required: true
+})
 export const recreate = core.getBooleanInput("recreate", {required: true})
 export const deleteOldComment = core.getBooleanInput("delete", {required: true})
 export const githubToken = core.getInput("GITHUB_TOKEN", {required: true})
diff --git a/src/main.ts b/src/main.ts
index 8307f70..ac8fa3f 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -6,6 +6,7 @@ import {
   deleteOldComment,
   githubToken,
   header,
+  hideDetails,
   pullRequestNumber,
   recreate,
   repo
@@ -14,6 +15,7 @@ import {
   createComment,
   deleteComment,
   findPreviousComment,
+  getBodyOf,
   updateComment
 } from "./comment"
 
@@ -50,7 +52,7 @@ async function run(): Promise<undefined> {
       return
     }
 
-    const previousBody = append ? previous.body : undefined
+    const previousBody = getBodyOf(previous, append, hideDetails)
     if (recreate) {
       await deleteComment(octokit, repo, previous.id)
       await createComment(