A heat pump device includes an air conditioning control device configured to switch the heat pump device among a plurality of operation modes including an air-heating operation mode in which an indoor heat exchanger serves as a radiator and an outdoor heat exchanger serves as a heat absorber, and an air-cooling operation mode in which the indoor heat exchanger serves as a heat absorber and the outdoor heat exchanger serves as a radiator. The air conditioning control device switch a refrigerant pipe such that refrigerant is, in the air-cooling operation mode, supplied to part of the outdoor heat exchanger serving as a refrigerant inlet in the air-heating operation mode.