A pneumatic tool includes a drive part configured to be driven by compressed air, a control valve configured to switch the presence or absence of operation of the drive part, an on-off valve part configured to switch the presence or absence of operation of the control valve, and a timer part configured to control the operation of the on-off valve part and switch the presence or absence of operation of the control valve after a lapse of a predetermined time. The timer part comprises a timer piston configured to move in one direction, and a timer piston cylinder configured to support the timer piston. The pneumatic tool comprises a throttle part configured to throttle the flow rate of air flowing into or flowing out from the timer piston cylinder, and an adjustment part configured to adjust an operating time of the timer piston.