A stator coil includes a coil group of coils of three phases of a U-phase, a V-phase and a W-phase, each including a plurality of straight portions inserted into slots of a stator core, the coil group being folded back in a state where input terminals and midpoint terminals are closely arranged, so that forward portions and backward portions of the plurality of straight portions are laminated, and the input terminals and the midpoint terminals of the respective three-phase coils are alternately arranged in a length direction of the stator coil.