When stator winding wires of respective phases are concentratedly wound on a plurality of tooth portions provided on a stator iron core via insulating bobbins the stator winding wires of the respective phases are wound in winding spaces in slot sides so that winding heights become gradually higher toward outside diameter sides from inside diameter sides of the insulating bobbins, and in spaces formed by the stator winding wires, at the radial insides of the insulating bobbins, at outsides in an axial direction relative to the stator winding wires, connecting wires of the stator winding wires of the respective phases and a neutral point at which distal ends thereof are star-connected are placed along the spaces.