VEHICLE AIR CONDITIONER

A heat pump device 20 is operated so as to make a switch between multiple operation modes including a first dehumidification and heating operation mode in which a refrigerant discharged from a compressor is circulated through a downstream interior heat exchanger 31, a first pressure reducing valve 52, an upstream interior heat exchanger 32, and an exterior heat exchanger 33 in this order so that the heat exchanger 31 functions as a radiator and the heat exchanger 32 functions as a heat absorber, and a second dehumidification and heating operation mode in which the refrigerant discharged from the compressor is circulated through the downstream interior heat exchanger 31, a second pressure reducing valve 53, the exterior heat exchanger 33, and the upstream interior heat exchanger 32 in this order so that the heat exchanger 31 functions as a radiator and the heat exchanger 32 functions as a heat absorber.