A countershaft (3) operably connected to a motor and a tool holding sleeve (11) for holding an end tool (22) are disposed in parallel with each other in a housing (1). A motion converting member (5) for converting rotational motion to reciprocating motion to hammer the end tool (22) is rotatably mounted on the countershaft (3). A first clutch (6) is installed between the countershaft (3) and the motion converting member (5). A clutch sleeve (25) that is connected to the countershaft (3) through a rotation transmission member and a second clutch (27) that is rotated together with the tool holding sleeve (11) and is movable along the longitudinal direction of the tool holding sleeve (11) are disposed on the outer periphery of the tool holding sleeve (l1). The second clutch (27) is installed so as to be engageable with and disengageable from the clutch sleeve (25).
