An air-conditioning apparatus (10, 10A, 110, 210, 310), comprising: a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a heat-source-side expansion device, and a circuit-circuit heat exchanger are connected via a refrigerant pipe and configured to circulate refrigerant; a heat medium circuit (5, 5A to 5C) in which a pump, the circuit-circuit heat exchanger, a load-side expansion device, and a load-side heat exchanger are connected via a heat medium pipe and configured to circulate a heat medium; and a control unit (25, 25A, 25C, 250), the circuit-circuit heat exchanger configured to exchange heat between the refrigerant circulating in the refrigerant circuit and the heat medium circulating in the heat medium circuit (5, 5A to 5C), wherein the air conditioning apparatus further comprises: an outdoor unit having the compressor and the heat-source-side heat exchanger; a heat exchange unit (2, 2A to 2C) having the heat-source-side expansion device, the circuit-circuit heat exchanger, the pump, and the control unit (25, 25A, 25C, 250); and an indoor unit having the load-side expansion device and the load-side heat exchanger, characterized by further comprising a radiator that is connected to the heat medium pipe and in that the control unit (25, 25A, 25C, 250) is attached to the radiator and in that the control unit (25, 25A, 25C, 250) is configured to being cooled via the radiator by the heat medium flowing in the heat medium pipe and in that the radiator is located between the load-side heat exchanger and an inlet of the circuit-circuit heat exchanger located downstream of the load-side heat exchanger. a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, a heat-source-side expansion device, and a circuit-circuit heat exchanger are connected via a refrigerant pipe and configured to circulate refrigerant; a heat medium circuit (5, 5A to 5C) in which a pump, the circuit-circuit heat exchanger, a load-side expansion device, and a load-side heat exchanger are connected via a heat medium pipe and configured to circulate a heat medium; and a control unit (25, 25A, 25C, 250), the circuit-circuit heat exchanger configured to exchange heat between the refrigerant circulating in the refrigerant circuit and the heat medium circulating in the heat medium circuit (5, 5A to 5C), wherein the air conditioning apparatus further comprises: an outdoor unit having the compressor and the heat-source-side heat exchanger; a heat exchange unit (2, 2A to 2C) having the heat-source-side expansion device, the circuit-circuit heat exchanger, the pump, and the control unit (25, 25A, 25C, 250); and an indoor unit having the load-side expansion device and the load-side heat exchanger, a heat exchange unit (2, 2A to 2C) having the heat-source-side expansion device, the circuit-circuit heat exchanger, the pump, and the control unit (25, 25A, 25C, 250); and an indoor unit having the load-side expansion device and the load-side heat exchanger, characterized by further comprising a radiator that is connected to the heat medium pipe and in that the control unit (25, 25A, 25C, 250) is attached to the radiator and in that the control unit (25, 25A, 25C, 250) is configured to being cooled via the radiator by the heat medium flowing in the heat medium pipe and in that the radiator is located between the load-side heat exchanger and an inlet of the circuit-circuit heat exchanger located downstream of the load-side heat exchanger.