AIR CONDITIONER

PROBLEM TO BE SOLVED: To provide an air conditioner which keeps standby power consumption low at shutdown.SOLUTION: The air conditioner includes an interior unit A6a equipped with an interior unit power supply part 8, an interior unit control part 9, and an interior unit communication means 7, and an exterior unit 1 equipped with an exterior unit power supply part 3, an outdoor unit controller 2, and an exterior unit communication means 4 where the exterior unit 1 is connected to a commercial alternating current power supply 5, electric power is supplied to the interior unit 6a through an indoor and outdoor connection lines A11 and B12, and signal transfer is performed between an exterior unit communication means 4 and an interior unit communication means 7 through indoor and outdoor connection lines B12 and C13. Because a power supply change means 14 switching the electric power supply to the interior unit power supply part 8 is arranged in the indoor and outdoor connection lines A11, a low voltage detection means 21 detecting a control voltage supplied to the interior unit control part 9 at the shutdown of the air conditioner is arranged, and a power supply change means 14 is turned on and off according to a voltage detected by the low voltage detection means 21, it is not necessary to supply continuous power to the interior unit A6a at the shutdown.