VEHICLE AIR-CONDITIONING DEVICE

There is disclosed a vehicle air-conditioning device in which a refrigerant subcool degree in a radiator is appropriately controlled, so that comfortable and efficient vehicle interior air conditioning is achievable. The vehicle air-conditioning device executes a heating mode in which a controller lets a refrigerant discharged from a compressor radiate heat in a radiator , decompresses the refrigerant by which heat has been radiated by an outdoor expansion valve , and then lets the refrigerant absorb heat in an outdoor heat exchanger . In the heating mode, the vehicle air-conditioning device controls a refrigerant subcool degree SC of the radiator by the outdoor expansion valve . On a basis of a radiator inlet air temperature THin that is a temperature of the air flowing into the radiator , the controller corrects a target subcool degree TGSC that is a target value of the refrigerant subcool degree SC in the radiator in a lowering direction, as the radiator inlet air temperature THin rises.