To provide an air conditioner for vehicles that can be miniaturized and made less expensive without any switches, such as relays, between a blower motor 13 and a battery 10, and does not generate any inconveniences of battery exhaustion even without any relays.

The air conditioner for vehicles comprises the blower motor 13; the battery 10; a power controller 30; and a control unit 20. The power controller 30 comprises a field effect transistor (FET) 35; and a drive circuit 33 for driving the FET 35. The drain electrode side of the FET 35 and the battery 10 are directly connected without through relays, or the like, and the source electrode side of the FET 35 and the blower motor 13 are connected. Further, the air conditioner for vehicles has a standby circuit 31 for applying voltage to the drive circuit 33 by turning on/off a standby switch 36, based on a command signal outputted from the control unit 20.