DRIVER

Provided is a driver configured so as to prevent the concentration of stress at a support section. This driver has: a strike section which moves in a first direction to strike a fastener; and a bumper coming into contact with the strike section and restricting the range of movement of the strike section in the first direction. The driver further has: a support section (13) for supporting the bumper; a connection section (51) connected to the support section (13) and disposed in a direction intersecting the first direction; a drive section supported by the connection section (51) and moving the strike section in a second direction; a first receiving section (92) which, when the strike section moves in the first direction to hit the bumper, receives a load acting on the support section (13) in the first direction; and a second receiving section (93) which, when the strike section moves in the first direction to hit the bumper, receives a load acting on the support section (13) in the circumferential direction about a first centerline of the drive section.