A motor apparatus includes: an inverter arranged to drive a motor with a voltage outputted from a driving element; a rectifier circuit arranged to rectify alternating-current power to generate direct-current power to be applied to the driving element; a measuring section arranged to measure a voltage of the direct-current power; and a control circuit arranged to control the inverter in accordance with a result of a measurement by the measuring section; wherein the control circuit is arranged to vary an amplitude value of a drive signal to be applied to a base or gate of the driving element in a complementary manner in relation to a fluctuation in the voltage of the direct-current power.