An air conditioner includes an outdoor unit, a relay circuit which includes a contact and a relay coil, and a control unit which causes a first voltage equal to or higher than an operating voltage or a second voltage lower than the operating voltage and equal to or higher than a retention voltage to be applied to the relay coil. One end portion of the contact is connected to an alternating-current power supply and the other end portion of the contact is connected to the outdoor unit. One end portion of the relay coil is connected to a power supply for driving the relay circuit. The control unit causes a second voltage to be applied to the relay coil after the contact is turned ON, and causes the first voltage to be applied to the relay coil at a predetermined constant period.