Abstract: A stator includes: a stator core with N pieces of slots ranging along an axial direction, which are formed side-by-side along a circumferential direction; and a stator winding installed in the slots at the stator winding. The stator winding includes a plurality of winding groups, each made up with N pieces of lap-wound coils each formed by winding a conductor wire a plurality of times. The winding groups are disposed in a plurality of layers set side-by-side along a radial direction at the stator core. One coil side at each of the lap-wound coils is inserted in a specific slot on an inner side along the radial direction in a specific layer and another coil side of the lap-wound coil is inserted in another slot on an outer side along the radial direction in the specific layer.