A pneumatic fastening device which uses compressed air from an internal reservoir to momentarily move a feed piston in a direction away from a drive channel when a trigger is actuated and a fastener is driven into a workpiece. The compressed air can flow from the reservoir to a return chamber by flowing through a passageway to pressurize the return chamber and move the feed piston away from the drive channel. The passageway can be a feed piston pressure tube which received compressed air from the reservoir, passes through one or more bulkheads that separate different chambers of the pneumatic fastening device and has an outlet in the return chamber.

There is provided a driving tool driven by air pressure of compressed air. The driving tool includes: a driving cylinder to which compressed air is supplied; a driving piston configured to move in an up-down direction inside the driving cylinder by the supplied compressed air; a driver attached to the driving piston and configured to move in the up-down direction; and a guide portion provided on a lower side of the driving cylinder. The guide portion has a guide hole through which the driver passes and an exhaust hole that allows an inside of the driving cylinder to communicate with an outside of the driving tool. The exhaust hole is provided at a position separated outward from an inner peripheral surface of the guide hole.