An alternator has a rotor and a stator. The stator has a cylindrical armature core wound with an armature wiring. The core has slots disposed along a circumferential direction of the core so as to surround the rotor. Each slot extends in an axial direction of the core and has accommodation regions aligned along a radial direction of the core. Each region receives the wiring. The regions of each slot includes an innermost region and an outermost region, respectively, disposed on both ends of the slot in the radial direction. The wiring has end portions, respectively, drawn out from the outermost regions of different slots, and the wiring has a return portion of which both ends are drawn out from the innermost regions of two different slots.