Provided is a heat pump device configured to collect heat both from outside air and another heat source. A controller calculates heat exchange amounts with use of heat exchange performance of each of an air heat-source heat exchanger and an underground heat-source heat exchanger in addition to an outside air temperature and an underground temperature. Then, in switching between a simultaneous operation of causing refrigerant to flow through both of the air heat-source heat exchanger and the underground heat-source heat exchanger and a single operation of selecting the air heat-source heat exchanger or the underground heat-source heat exchanger to cause refrigerant to flow therethrough, the controller selects a heat source having a larger calculated heat exchange amount. In this manner, an appropriate heat source suitable for operation conditions can be selected.