PURPOSE: To enhance the suture operability by making a configuration to accommodate a pneumatic unit inside the frame to drive the actuator via the jetted-out low pressure gas by operating the handle, and so as to hammer in a surgical fastener via an anvil member. CONSTITUTION: The device 50 for hammering in a surgical fastener consists of a long main body 54 extended from the frame 52 and a cartridge assembly 58. This device is also provided with an anvil member 56 equipped with a fastener-formed surface. This anvil member 56 is set so that its free movement can be made between the opened/closed positions by operating the joint-type handle 62. The frame 52 accommodates a pneumatic unit devised so that the low pressure gas passed through the valve opened by operating the handle 62 can drive the pneumatic actuator. Operating this pneumatic actuator is engineered to activate the launching trigger to drive the anvil member 56 via the linkage/cable assembly and others.