In a gas combustion type striking tool which strikes a fastener supplied in a nose portion into a member to be fastened by burning mixed gas inside a combustion chamber above a striking cylinder in accordance with a pulling operation of a trigger lever to drive a striking piston and a driver by a pressure of the combustion gas thus generated, a topper is disposed so as to be able to protrude into a path of a feed pawl or a feed piston, and a stopper engaging member, which extends downward from the striking cylinder and is movable in a vertical direction, engages with the stopper when the stopper engaging member moves downward, thereby retracting the stopper from the path.