A hammer drill includes a main body which houses a driving motor having a brush and a brush holder unit which holds the brush and switches a position of the brush, and a main handle which is movable to the main body. Further, a coil spring which biases the handle is provided. In a state that the coil spring biases the handle, the handle is moved against the main body in a longitudinal direction of a hammer bit and vibration transmission from the main body to the handle is prevented. Further, interference of a lever of the brush holder unit and the handle is prevented by a part of an opening formed on the handle.