To enhance the heat collecting efficiency of a refrigerant of a compression type heat pump, in a heat pump system wherein the heat of low temperature of a heat source is pumped up to be made high by the compression type heat pump and thereby a heat-driven heat pump is driven.

The compression type heat pump 20 is interposed between the heat-driven heat pump 10 of an absorption type and a fuel cell 30. A direct heat collecting path 31 is held in the fuel cell 30 and the opposite ends of this heat collecting path 31 communicate with the internal space of an evaporator 24. The refrigerant in the evaporator 24 of the heat pump 20 is led to the heat collecting path 31 and receives the exhaust heat of the fuel cell 30 to be heated directly and then the refrigerant is returned to the evaporator 24.