At once; immediately; without delay — used to indicate prompt action or response.
ご連絡ありがとうございます。早速確認してご返事します。
Thank you for contacting me. I will check it right away and reply.
問題が見つかったので、早速対策を講じた。
A problem was found, so we took countermeasures immediately.
早速ですが、会議を始めたいと思います。
Without further ado, I'd like to start the meeting.
提案を受けて彼は早速取りかかった。
After receiving the proposal, he got to work on it right away.