Electrical insulation properties of winding start ends or terminal ends of insulating coating electric wires of coils wound around polar teeth of a stator core are improved, and creeping and spatial distances for electrical insulation are secured. Wall portions which project toward an interior of a radial direction or an exterior of an axial direction of a stator core and which have electrical insulation properties are formed in an inner peripheral portion of the stator core of a motor, groove portions are formed in the wall portions and winding start ends or terminal ends of insulating coating electric wires of coils are arranged in the groove portions.