It is an object of the invention to provide a technique for reducing vibration by counter weights which smoothly operate without linearly reciprocating, in a reciprocating
power tool.The reciprocating
power tool has first and second bevel gears 123, 147 which are opposed to each other on either side of a
pinion 119 and rotationally driven in opposite directions at the same
reduction ratio by the
pinion 119. Further, the reciprocating
power tool has a slider 107 which is caused to linearly reciprocate in a longitudinal direction of a
tool bit 111 by a
crank 129. The first and second bevel gears 123, 147 are provided with first and second counter weights 143, 145 in positions displaced from their rotation axes, respectively. When the first counter weight 143 and the second counter weight 145 revolve, components of the revolving motion in the longitudinal direction of the
tool bit oppositely move with respect to
linear motion of the slider 107, and the first counter weight 143 and the second counter weight 145 move in the same phase in the longitudinal direction of the
tool bit 111 and are disposed on opposite sides of the rotation axis and at the same distance from the rotation axis in a direction transverse to the longitudinal direction of the tool bit 111.