To provide a further efficient heat pump system by eliminating a loss caused between an energy generating place and an energy consuming place.

This engine heat pump system comprises an engine 5 housed in a casing 4; a compressor 7 driven by the engine 5; an indoor unit heat exchanger to which a refrigerant pressurized by the compressor 7 is guided; an expansion valve 13 for reducing the pressure of the refrigerant discharged from the heat exchanger 11; and an outdoor unit heat exchaner 15, in which the refrigerant is guided through the expansion valve 13 and heat-exchanged with the outside air. In this pump system, a waste heat recovering heat exchanger 17, in which the refrigerant is guided through the expansion valve 13 and heat-exchanged with the air within the case 4, is further provided in parallel with the outdoor unit heat exchanger 15. In heating operation, the refrigerant raised in temperature by being pressurized by the compressor 7 is guided to the indoor unit heat exchanger 11 to radiate heat into a room. Further, the refrigerant absorbs heat from the outside air in the outdoor unit heat exchanger 15, and also recovers at least the waste heat of the engine 5 in the waste heat heat exchanger 17.