In order to increase the evaporation capacity of a use-side heat exchanger regardless of operating conditions, a suction injection pipe (61) and a subcooling heat exchanger (62) are provided at a main refrigerant circuit (20) in which a main refrigerant circulates. Further, a sub-refrigerant circuit (80) that differs from the main refrigerant circuit (20) and in which a sub-refrigerant circulates is provided. A control unit (9) performs control for switching between a cooling action of the subcooling heat-exchanger that cools the main refrigerant that is sent to a main use-side heat exchanger (72a, 72b) by using the suction injection pipe (61) and the subcooling heat exchanger (62), and a cooling action of the sub-refrigerant-circuit that cools the main refrigerant that is sent to the main use-side heat exchanger (72a, 72b) by using the sub-refrigerant circuit 80.