A driving tool includes a striking mechanism configured to be actuated by a combustion pressure of a mixed gas of compressed air and fuel, a combustion chamber in which the mixed gas of compressed air and fuel is to be combusted, a valve member configured to open and close communication between the striking mechanism and the combustion chamber, and a valve support member configured to support the valve member. The valve member has a seal part provided on an outer peripheral surface along a moving direction of the valve member.