An electric power tool, comprising: a motor; a speed reduction mechanism for transferring the power of the motor; a power output unit driven by the power transferred through the speed reduction mechanism; a control circuit unit for controlling rotation of the motor; and a housing for accommodating the motor, the speed reduction mechanism, the power output unit and the control circuit unit, the housing provided with an air supply-exhaust hole, wherein the motor includes: a stator core wound with coils; a rotor core provided with a magnet; an electronic circuit unit connected to the coils and the control circuit unit, wherein the electronic circuit unit includes a circuit board, electronic components arranged on the circuit board and including a switching element for turning on or off the electric power supplied to the coils, coil connection portions arranged on the circuit board and connected to the coiis and a control circuit connection portion arranged on the circuit board and connected to the control circuit unit; a radiator member for dissipating heat generated in the switching element of the electronic circuit unit; characterized in that an insulating cover member is molded to cover the electronic components, the coil connection portions, the control circuit connection portion, the circuit board and the radiator member against exposure. a motor; a speed reduction mechanism for transferring the power of the motor; a power output unit driven by the power transferred through the speed reduction mechanism; a control circuit unit for controlling rotation of the motor; and a housing for accommodating the motor, the speed reduction mechanism, the power output unit and the control circuit unit, the housing provided with an air supply-exhaust hole, wherein the motor includes: a stator core wound with coils; a rotor core provided with a magnet; an electronic circuit unit connected to the coils and the control circuit unit, a stator core wound with coils; a rotor core provided with a magnet; an electronic circuit unit connected to the coils and the control circuit unit, wherein the electronic circuit unit includes a circuit board, electronic components arranged on the circuit board and including a switching element for turning on or off the electric power supplied to the coils, coil connection portions arranged on the circuit board and connected to the coiis and a control circuit connection portion arranged on the circuit board and connected to the control circuit unit; a circuit board, electronic components arranged on the circuit board and including a switching element for turning on or off the electric power supplied to the coils, coil connection portions arranged on the circuit board and connected to the coiis and a control circuit connection portion arranged on the circuit board and connected to the control circuit unit; a radiator member for dissipating heat generated in the switching element of the electronic circuit unit; characterized in that an insulating cover member is molded to cover the electronic components, the coil connection portions, the control circuit connection portion, the circuit board and the radiator member against exposure.