In an electric power tool which houses a motor and a controller for controlling drive of the motor, the controller has a circuit board on which electric components are mounted and a heat radiation member which radiates heat of the electric components. The heat radiation member has a facing part which faces the circuit board in parallel to a board surface of the circuit board. The facing part is provided with steps by which a distance between the facing part and the board surface of the circuit board varies. Furthermore, the facing part of the heat radiation member is provided with a first facing part in which a relative distance with respect to the board surface of the circuit board is reduced.