To obtain a floor heating unit for engine driven heat pump in which a heat pump can be remodeled easily for floor heating and the temperature and pressure of refrigerant in the upstream of a floor heating unit and an expansion valve do not take an undue level even under heavy load.

A refrigerant radiator, i.e., a refrigerant side radiator 418 for floor heating, passing high temperature high pressure refrigerant in the upstream of an indoor heat exchanger for heating, an engine cooling water radiator, i.e., a cooling water side radiator 403 for floor heating, passing the cooling water after absorbing engine exhaust heat, a refrigerant side heat receiver 414 for transporting heat to a panel for indoor floor heating, an engine cooling water side heat receiver 415 and a liquid circulation pump 413 are contained in one case. A refrigerant inlet/outlet and an engine cooling water inlet/outlet are made in one of two internally facing side faces of the case while an inlet/ outlet for transporting heat from the floor heating panel is made in the other side face. In the case, the heat transporting liquid receives heat from refrigerant and then from the engine cooling water and transports the heat to the floor heating panel.