An AC motor is provided. In the AC motor, there are M pieces (M is an integer of 3 or more) of stator pole groups SPG are arranged in a rotor axis direction, where each of the stator poles groups is composed of a plurality of stator poles which are for the same phase and arranged in a circumferential direction of the motor. Between the stator pole groups SPG, “M−1” pieces of annular windings WR are arranged which allow one-way current to flow therethrough. The windings WR are arranged such that the directions of current passing therethrough are reversed in turn in the rotor axis direction. The stator pole groups SPG are excited to generate magnetic fluxes φG directed in a one way. The excited directions of the magnetic fluxes φG are reversed in turn in the rotor axis direction.