2FA セットアップガイド

Google アカウントで 2FA を有効にする方法

2026年6月5日を更新しました

2 要素認証 (2FA) は、パスワードが漏洩した場合でも、Google アカウントを保護します。 iPhone、iPad、または Mac で Authenticator App を使用して Google 検証コードを生成するには、以下の手順に従ってください。

Download Authenticator App
Download Authenticator App from the App Store on your iPhone, iPad or Mac. It's free and no sign-up is required.
Open your Google Account settings
On a computer, go to myaccount.google.com, or click your profile picture and choose “Manage your Google Account”.
Go to Security and open 2-Step Verification
Select “Security” in the left menu, then under “How you sign in to Google” click “2-Step Verification” and follow the prompts to turn it on.
Choose the Authenticator app option
From the list of second steps, find “Authenticator app” and click “Set up”. Google will display a QR code.
Scan the QR code with Authenticator App
Open Authenticator App, tap the + button and scan the QR code shown by Google. If you can't scan it, choose the manual option on Google and type the setup key into the app instead.
Enter the 6-digit verification code
Type the 6-digit code from Authenticator App back into Google to confirm the setup. The code refreshes every 30 seconds.
Save your backup codes
If Google offers backup or recovery codes, download or write them down and store them somewhere safe. They let you regain access if you ever lose your device.