A rotary electric machine driving device that drives and controls an alternating-current rotary electric machine, the rotary electric machine driving device including: an inverter that is electrically interposed between a direct-current power supply and the rotary electric machine, and converts electric power between a direct current and an alternating current; a smoothing capacitor that is electrically interposed between the direct-current power supply and the inverter, and is connected between a positive pole and a negative pole on a direct-current side of the inverter; and an inverter control unit that controls switching of a switching element of the inverter according to a predefined switching frequency.