An air-conditioning apparatus comprising: a refrigerant circuit in which a compressor, a heat source side heat exchanger, an expansion device (26a, 26b), and an intermediate heat exchanger (25a, 25b) configured to exchange heat between refrigerant and a heat medium are connected by a refrigerant pipe, the refrigerant flowing through the refrigerant circuit; a heat medium circuit in which a pump (31a, 31b) configured to convey the heat medium, a plurality of use side heat exchangers (35a, 35b, 35c, 35d), a plurality of heat medium flow control devices (34a, 34b, 34c, 34d), and the intermediate heat exchanger (25a, 25b) are connected by a heat medium pipe, the heat medium flowing through the heat medium circuit, the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) each being configured to control a flow rate of the heat medium flowing through a corresponding one of the plurality of use side heat exchangers (35a, 35b, 35c, 35d); an air discharge device including a heat medium tank connected to the heat medium circuit and configured to separate air from the heat medium in the heat medium circuit, and an air vent valve provided at the heat medium tank and configured to discharge the air, and a controller configured to drive the plurality of heat medium flow control devices (34a, 34b, 34c, 34d); characterized in that the controller is configured to drive the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) such that an air vent mode executed in which the air is discharged, one of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) being opened while remaining one or more of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) are closed to discharge the air and then the opened one of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) being sequentially switched to repeatedly discharge the air. a refrigerant circuit in which a compressor, a heat source side heat exchanger, an expansion device (26a, 26b), and an intermediate heat exchanger (25a, 25b) configured to exchange heat between refrigerant and a heat medium are connected by a refrigerant pipe, the refrigerant flowing through the refrigerant circuit; a heat medium circuit in which a pump (31a, 31b) configured to convey the heat medium, a plurality of use side heat exchangers (35a, 35b, 35c, 35d), a plurality of heat medium flow control devices (34a, 34b, 34c, 34d), and the intermediate heat exchanger (25a, 25b) are connected by a heat medium pipe, the heat medium flowing through the heat medium circuit, the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) each being configured to control a flow rate of the heat medium flowing through a corresponding one of the plurality of use side heat exchangers (35a, 35b, 35c, 35d); an air discharge device including a heat medium tank connected to the heat medium circuit and configured to separate air from the heat medium in the heat medium circuit, and an air vent valve provided at the heat medium tank and configured to discharge the air, and a controller configured to drive the plurality of heat medium flow control devices (34a, 34b, 34c, 34d); characterized in that the controller is configured to drive the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) such that an air vent mode executed in which the air is discharged, one of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) being opened while remaining one or more of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) are closed to discharge the air and then the opened one of the plurality of heat medium flow control devices (34a, 34b, 34c, 34d) being sequentially switched to repeatedly discharge the air.