A vehicle air conditioner (1A) includes: an external air introduction port (33) for introducing external air into a vehicle interior; and a duct (3) having an inlet port (31) for drawing internal air into the duct and an outlet port (32) for blowing air into the vehicle interior. In the duct (3), a first indoor heat exchanger (12A) and a second indoor heat exchanger (12B) of a heat pump circuit (2A) are disposed. The first indoor heat exchanger (12A) contributes mainly to heating, and the second indoor heat exchanger (12B) contributes mainly to cooling. The duct (3) is provided with at least one of a heating exhaust port (34) for discharging air cooled in the second indoor heat exchanger (12B) to the outside of the vehicle interior in heating operation and a cooling exhaust port (35) for discharging air heated in the first indoor heat exchanger (12A) to the outside of the vehicle interior in cooling operation. With the above configuration, energy required for adjustment of the temperature of air in the vehicle interior can be efficiently used without waste.