An object of the present invention to enhance reliability with smooth operation in the presence of a standby power reduction unsupporting model that cannot transition to a suspended state. An air conditioner (1) includes a selection mechanism (16) that prevents a current flow in a power supply wiring (1a) in an operation stop period and determines whether to adapt an outdoor unit (10) to a unit that is able to transition to a suspended state in which no electric power is supplied to the outdoor unit (10). The selection mechanism (16) is provided in the power supply wiring (1a), and includes a relay (K13R) that prevents a current flow in the power supply wiring (1a) in the operation stop period to cause the air conditioner to transition to the suspended state in which no electric power is supplied to the outdoor unit (10), an auxiliary circuit (16a) provided in parallel with the relay (K13R) and configured to always supply electric power to the outdoor control circuit (13), and an opening/closing unit (17) provided in the auxiliary circuit (16a) and configured to open and close the auxiliary circuit (16a). The opening/closing unit (17) is a connector.