An air-conditioning device, comprising: a refrigerant circuit including a compressor, a heat source-side heat exchanger, an expansion unit, and an intermediate heat exchanger that are connected by a refrigerant pipe, and through which refrigerant circulates, the heat source-side heat exchanger exchanging heat between air and the refrigerant, the intermediate heat exchanger exchanging heat between the refrigerant and heat medium; a heat medium circuit including a pump, the intermediate heat exchanger, and a load-side heat exchanger that are connected by a heat medium pipe, and through which the heat medium circulates, the load-side heat exchanger exchanging heat between air in an air-conditioned space and the heat medium; a discharge unit connected downstream of the intermediate heat exchanger in the heat medium circuit and configured to discharge fluid flowing through the heat medium pipe, to outside of the heat medium pipe, depending on pressure of the fluid; a refrigerant detection device configured to detect concentration of the refrigerant contained in the fluid discharged from the discharge unit; a notification device configured to notify leakage of the refrigerant; and controller configured to activate the notification device depending on the concentration of the refrigerant detected by the refrigerant detection device, characterised in that in a case where the concentration of the refrigerant detected by the refrigerant detection device exceeds a first stop set value that is a preset threshold of refrigerant concentration, the controller being configured to stop the pump, in a case where, after a set time elapses, the concentration of the refrigerant detected by the refrigerant detection device is lower than or equal to a reoperation set value that is a preset threshold of refrigerant concentration, the controller being configured to activate the stopped pump. a refrigerant circuit including a compressor, a heat source-side heat exchanger, an expansion unit, and an intermediate heat exchanger that are connected by a refrigerant pipe, and through which refrigerant circulates, the heat source-side heat exchanger exchanging heat between air and the refrigerant, the intermediate heat exchanger exchanging heat between the refrigerant and heat medium; a heat medium circuit including a pump, the intermediate heat exchanger, and a load-side heat exchanger that are connected by a heat medium pipe, and through which the heat medium circulates, the load-side heat exchanger exchanging heat between air in an air-conditioned space and the heat medium; a discharge unit connected downstream of the intermediate heat exchanger in the heat medium circuit and configured to discharge fluid flowing through the heat medium pipe, to outside of the heat medium pipe, depending on pressure of the fluid; a refrigerant detection device configured to detect concentration of the refrigerant contained in the fluid discharged from the discharge unit; a notification device configured to notify leakage of the refrigerant; and controller configured to activate the notification device depending on the concentration of the refrigerant detected by the refrigerant detection device, characterised in that in a case where the concentration of the refrigerant detected by the refrigerant detection device exceeds a first stop set value that is a preset threshold of refrigerant concentration, the controller being configured to stop the pump, in a case where, after a set time elapses, the concentration of the refrigerant detected by the refrigerant detection device is lower than or equal to a reoperation set value that is a preset threshold of refrigerant concentration, the controller being configured to activate the stopped pump.