A method for manufacturing an alternator includes preparing a winding assembly formed by bending strands of wire so as to have straight portions which fit into slots, forming a base core by laminating plate-shaped magnetic members formed with the slots, stacking the winding assembly on the base core and pressing the winding assembly such that the straight portions enter the slots, and forming the stator core by bending the base core into a cylindrical shape and abutting end surfaces of the base core.