To provide a heat pump unit capable of preventing freezing of condensate water from an air heat exchanger and simultaneously improving energy consumption efficiency (COP) of the heat pump unit with a simple constitution.

A water circuit 20 for circulating the water, is constituted to allow the water supplied from an external connection port 21 to pass near a bottom portion of the air heat exchanger 3 exchanging heat between a refrigerant and the outdoor air, and then to flow into a water heat exchanger 2 exchanging heat between the refrigerant and the water. Thus the water supplied from the external connection port 21 is cooled by the heat exchange with the condensate from the air heat exchanger 3 near the bottom portion of the air heat exchanger 3, and flows into the water heat exchanger. On the other hand, the condensate from the air heat exchanger 3 is heated near the bottom portion of the air heat exchanger 3 to prevent its freezing.