An SR motor includes a stator having a plurality of salient poles and a rotor having another plurality of salient poles. Windings are wound around the plurality of salient poles and magnetic fields are generated in the plurality of salient poles. The number of salient poles of the rotor is determined depending upon a number of the salient poles of the stator. A supply mode for supplying power from a power supply to the windings, a reflux mode for setting both terminals of the windings to an identical potential, and a regenerative mode for recovering an electromotive force generated in the windings into the power supply are executed as the rotor rotates. The reflux mode and the regenerative mode are preferably repeated in a period during which the inductance of the windings is reduced as the rotor rotates.