A vehicle air conditioner (1A, 1B) that cools and heats a vehicle interior, the vehicle air conditioner (1A, 1B) comprising: an external air introduction port for introducing external air into the vehicle interior; a duct having an inlet port for drawing internal air of the vehicle interior into the duct, and an outlet port for blowing air into the vehicle interior; an air blower that generates an air flow from the inlet port to the outlet port in the duct; and a heat pump circuit (2A, 2B) comprising a first indoor heat exchanger that is disposed in the duct and contributes mainly to heating, a second indoor heat exchanger that is disposed in the duct and contributes mainly to cooling, and an outdoor heat exchanger that is disposed outside the vehicle interior, functions as an evaporator in heating operation, and functions as a condenser in cooling operation, characterized in that the duct is provided with at least one of a heating exhaust port for discharging air cooled in the second indoor heat exchanger to the outside of the vehicle interior in the heating operation, and a cooling exhaust port for discharging air heated in the first indoor heat exchanger to the outside of the vehicle interior in the cooling operation, the second indoor heat exchanger is located on a windward side in the duct with respect to the first indoor heat exchanger, the first indoor heat exchanger is disposed in the duct in such a manner that a first flow path passing through the first indoor heat exchanger and a second flow path not passing through the first indoor heat exchanger are formed, a first adjustment damper is provided in the duct and adjusts a ratio between an amount of air flowing in the first flow path and an amount of air flowing in the second flow path, and the first adjustment damper is provided so as to be selectively operable to block the first flow path or block the second flow path. an external air introduction port for introducing external air into the vehicle interior; a duct having an inlet port for drawing internal air of the vehicle interior into the duct, and an outlet port for blowing air into the vehicle interior; an air blower that generates an air flow from the inlet port to the outlet port in the duct; and a heat pump circuit (2A, 2B) comprising a first indoor heat exchanger that is disposed in the duct and contributes mainly to heating, a second indoor heat exchanger that is disposed in the duct and contributes mainly to cooling, and an outdoor heat exchanger that is disposed outside the vehicle interior, functions as an evaporator in heating operation, and functions as a condenser in cooling operation, a first indoor heat exchanger that is disposed in the duct and contributes mainly to heating, a second indoor heat exchanger that is disposed in the duct and contributes mainly to cooling, and an outdoor heat exchanger that is disposed outside the vehicle interior, functions as an evaporator in heating operation, and functions as a condenser in cooling operation, the duct is provided with at least one of a heating exhaust port for discharging air cooled in the second indoor heat exchanger to the outside of the vehicle interior in the heating operation, and a cooling exhaust port for discharging air heated in the first indoor heat exchanger to the outside of the vehicle interior in the cooling operation, the second indoor heat exchanger is located on a windward side in the duct with respect to the first indoor heat exchanger, the first indoor heat exchanger is disposed in the duct in such a manner that a first flow path passing through the first indoor heat exchanger and a second flow path not passing through the first indoor heat exchanger are formed, a first adjustment damper is provided in the duct and adjusts a ratio between an amount of air flowing in the first flow path and an amount of air flowing in the second flow path, and the first adjustment damper is provided so as to be selectively operable to block the first flow path or block the second flow path.