diff --git a/src/mock/engineMock/index.ts b/src/mock/engineMock/index.ts
index 19142fa1c4..e85f1a646f 100644
--- a/src/mock/engineMock/index.ts
+++ b/src/mock/engineMock/index.ts
@@ -107,6 +107,8 @@ export function createOpenAPIEngineMock(): DefaultApiInterface {
         volumeScale: 1.0,
         prePhonemeLength: 0.1,
         postPhonemeLength: 0.1,
+        pauseLength: null,
+        pauseLengthScale: 1.0,
         outputSamplingRate: getEngineManifestMock().defaultSamplingRate,
         outputStereo: false,
       };
diff --git a/src/mock/engineMock/manifestMock.ts b/src/mock/engineMock/manifestMock.ts
index 4a32cf957b..a4e4d7437c 100644
--- a/src/mock/engineMock/manifestMock.ts
+++ b/src/mock/engineMock/manifestMock.ts
@@ -26,7 +26,8 @@ export function getEngineManifestMock() {
       adjustPitchScale: true,
       adjustIntonationScale: true,
       adjustVolumeScale: true,
-      interrogativeUpspeak: false,
+      adjustPauseLength: true,
+      interrogativeUpspeak: true,
       synthesisMorphing: false,
       sing: true,
       manageLibrary: false,
diff --git a/src/mock/engineMock/talkModelMock.ts b/src/mock/engineMock/talkModelMock.ts
index ed17bd62db..85ceb87126 100644
--- a/src/mock/engineMock/talkModelMock.ts
+++ b/src/mock/engineMock/talkModelMock.ts
@@ -178,7 +178,7 @@ export async function textToActtentPhrasesMock(text: string, styleId: number) {
       const pauseMora = {
         text: "、",
         vowel: "pau",
-        vowelLength: 1 - 1 / (accentPhrases.length + 1),
+        vowelLength: 1 - 1 / (accentPhrases.length + 2),
         pitch: 0,
       };
 
diff --git a/tests/e2e/browser/utility.ts b/tests/e2e/browser/utility.ts
new file mode 100644
index 0000000000..b00bf3fcc0
--- /dev/null
+++ b/tests/e2e/browser/utility.ts
@@ -0,0 +1,81 @@
+import { Page } from "@playwright/test";
+import { Brand } from "@/type/utility";
+import { success } from "@/type/result";
+
+type TestFileId = Brand<string, "TestFileId">;
+
+/** ファイル書き出し選択ダイアログをモックにする */
+// TODO: モックを戻せるようにする
+export async function mockShowSaveFileDialog(page: Page): Promise<{
+  getFileIds: () => Promise<TestFileId[]>;
+}> {
+  type _Window = Window & {
+    _mockShowSaveFileDialog: {
+      returnValues: TestFileId[];
+    };
+  };
+
+  // モックを差し込む
+  await page.evaluate(() => {
+    const _window = window as unknown as _Window;
+    _window._mockShowSaveFileDialog = {
+      returnValues: [],
+    };
+
+    _window.backend.showSaveFileDialog = async () => {
+      const id = `${Date.now()}` as TestFileId;
+      _window._mockShowSaveFileDialog.returnValues.push(id);
+      return id;
+    };
+  });
+
+  return {
+    getFileIds: async () => {
+      return page.evaluate(() => {
+        const _window = window as unknown as _Window;
+        return _window._mockShowSaveFileDialog.returnValues;
+      });
+    },
+  };
+}
+
+/** ファイル書き出しをモックにする */
+// TODO: モックを戻せるようにする
+export async function mockWriteFile(page: Page): Promise<{
+  getWrittenFileBuffers: () => Promise<Record<string | TestFileId, Buffer>>;
+}> {
+  type _Window = Window & {
+    _mockWriteFile: Record<string | TestFileId, Uint8Array>;
+  };
+
+  // モックを差し込む
+  await page.evaluate(
+    ({ sucecssResult }) => {
+      const _window = window as unknown as _Window;
+      _window._mockWriteFile = {};
+
+      _window.backend.writeFile = async ({ filePath, buffer }) => {
+        _window._mockWriteFile[filePath] = new Uint8Array(buffer);
+        return sucecssResult;
+      };
+    },
+    { sucecssResult: success(undefined) },
+  );
+
+  return {
+    getWrittenFileBuffers: async () => {
+      const arrays = await page.evaluate(() => {
+        const _window = window as unknown as _Window;
+        return Object.fromEntries(
+          Object.entries(_window._mockWriteFile).map(([key, value]) => [
+            key,
+            Array.from(value),
+          ]),
+        );
+      });
+      return Object.fromEntries(
+        Object.entries(arrays).map(([key, value]) => [key, Buffer.from(value)]),
+      );
+    },
+  };
+}
diff --git "a/tests/e2e/browser/\343\202\271\343\202\257\343\203\252\343\203\274\343\203\263\343\202\267\343\203\247\343\203\203\343\203\210.spec.ts-snapshots/\343\203\210\343\203\274\343\202\257\347\224\273\351\235\242-browser-win32.png" "b/tests/e2e/browser/\343\202\271\343\202\257\343\203\252\343\203\274\343\203\263\343\202\267\343\203\247\343\203\203\343\203\210.spec.ts-snapshots/\343\203\210\343\203\274\343\202\257\347\224\273\351\235\242-browser-win32.png"
index 54332e013d..f2a6505843 100644
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diff --git "a/tests/e2e/browser/\351\237\263\345\243\260\346\233\270\343\201\215\345\207\272\343\201\227.spec.ts" "b/tests/e2e/browser/\351\237\263\345\243\260\346\233\270\343\201\215\345\207\272\343\201\227.spec.ts"
new file mode 100644
index 0000000000..84a239a773
--- /dev/null
+++ "b/tests/e2e/browser/\351\237\263\345\243\260\346\233\270\343\201\215\345\207\272\343\201\227.spec.ts"
@@ -0,0 +1,80 @@
+import { test, expect, Page } from "@playwright/test";
+import { gotoHome, navigateToMain } from "../navigators";
+import { getQuasarMenu } from "../locators";
+import { mockShowSaveFileDialog, mockWriteFile } from "./utility";
+
+test.beforeEach(gotoHome);
+
+async function exportSelectedAudioAndSnapshot(page: Page, name: string) {
+  const { getFileIds } = await mockShowSaveFileDialog(page);
+  const { getWrittenFileBuffers } = await mockWriteFile(page);
+
+  await test.step("選択音声を書き出す", async () => {
+    await page.getByRole("button", { name: "ファイル" }).click();
+    await getQuasarMenu(page, "選択音声を書き出し").click();
+  });
+
+  await test.step("書き出し完了の通知を確認して閉じる", async () => {
+    const notify = page.locator("#q-notify");
+    await expect(notify.getByText("音声を書き出しました")).toBeVisible();
+    await notify.getByRole("button", { name: "閉じる" }).click();
+    await expect(notify).not.toBeVisible();
+  });
+
+  await test.step("音声ファイルのバイナリをスナップショット", async () => {
+    const fileId = (await getFileIds())[0];
+    const buffer = (await getWrittenFileBuffers())[fileId];
+    expect(buffer).toMatchSnapshot(`${name}.wav`);
+  });
+}
+
+test.describe("音声書き出し", () => {
+  test.skip(process.platform !== "win32", "Windows以外のためスキップします");
+
+  test.beforeEach(async ({ page }) => {
+    await navigateToMain(page);
+
+    await test.step("テキスト欄にテキストを入力", async () => {
+      const audioCell = page.getByRole("textbox", { name: "1行目" });
+      const accentPhrase = page.locator(".accent-phrase");
+
+      await audioCell.click();
+      await audioCell.fill("こんにちは、テストです");
+      await audioCell.press("Enter");
+      await expect(accentPhrase).not.toHaveCount(0);
+    });
+  });
+
+  test("各パラメータを変更して音声書き出し", async ({ page }) => {
+    await exportSelectedAudioAndSnapshot(page, "デフォルト");
+
+    const parameters = [
+      ["話速", "1.5"],
+      ["音高", "0.5"],
+      ["抑揚", "1.5"],
+      ["音量", "1.5"],
+      ["間の長さ", "1.5"],
+      ["開始無音", "0.3"],
+      ["終了無音", "0.3"],
+    ] as const;
+
+    for (const [name, newValue] of parameters) {
+      await test.step(`${name}変更`, async () => {
+        const input = page.getByLabel(name);
+        const originalValue = await input.inputValue();
+
+        await test.step("パラメータを変更", async () => {
+          await input.fill(newValue);
+          await input.press("Enter");
+        });
+
+        await exportSelectedAudioAndSnapshot(page, `${name}変更`);
+
+        await test.step("元の値に戻す", async () => {
+          await input.fill(originalValue);
+          await input.press("Enter");
+        });
+      });
+    }
+  });
+});
diff --git "a/tests/e2e/browser/\351\237\263\345\243\260\346\233\270\343\201\215\345\207\272\343\201\227.spec.ts-snapshots/\343\203\207\343\203\225\343\202\251\343\203\253\343\203\210-browser-win32.wav" "b/tests/e2e/browser/\351\237\263\345\243\260\346\233\270\343\201\215\345\207\272\343\201\227.spec.ts-snapshots/\343\203\207\343\203\225\343\202\251\343\203\253\343\203\210-browser-win32.wav"
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diff --git a/tests/unit/mock/engineMock/__snapshots__/index.spec.ts.snap b/tests/unit/mock/engineMock/__snapshots__/index.spec.ts.snap
index 87315b839a..4c0dcf11de 100644
--- a/tests/unit/mock/engineMock/__snapshots__/index.spec.ts.snap
+++ b/tests/unit/mock/engineMock/__snapshots__/index.spec.ts.snap
@@ -53,6 +53,8 @@ exports[`createOpenAPIEngineMock > audioQueryAudioQueryPost 1`] = `
   "intonationScale": 1,
   "outputSamplingRate": 24000,
   "outputStereo": false,
+  "pauseLength": null,
+  "pauseLengthScale": 1,
   "pitchScale": 0,
   "postPhonemeLength": 0.1,
   "prePhonemeLength": 0.1,