The present invention provides a refrigeration cycle device (50) which includes a main refrigerant circuit (21) having a compressor (1), a heat radiator (2), a first expansion mechanism (5), a second expansion mechanism (6), and an evaporator (4); an injection path (22) for supplying refrigerant having an intermediate pressure to an injection port (1c) of the compressor (1); and a water circuit (30) in which water to be heated by the heat radiator (2) flows. The refrigeration cycle device (50) further has an auxiliary heat exchanger (3). The auxiliary heat exchanger (3) exchanges heat betweenthe refrigerant flowing in the injection path (22) and the water present in the water circuit (30) and in a state before being heated by the heat radiator (2), and thus the auxiliary heat exchanger (3) cools the water.