A driving device includes an operable striking unit, a piston upper chamber configured to operate the striking unit by gas pressure, a housing, a head cap provided in the housing, a passage provided in the head cap, and an exhaust valve operably provided in the housing and configured to open and close the passage. The exhaust valve includes a contact portion and a non-contact portion, the contact portion comes into and out of contact with the head cap on an outer side of the passage in a radial direction of the passage, the non-contact portion is provided on an inner side of the contact portion in the radial direction of the passage, and the non-contact portion is provided at a position separated from the head cap in a state where die contact portion is in contact with the head cap.