An air-conditioning apparatus includes at least one system including a heat-medium conveying device, a heat-medium flow regulator, and a heat-medium flow control device, as a heat medium system capable of regulating a flow rate of a heat medium supplied to a heat source device-side heat exchanger exchanging heat between refrigerant and the heat medium. The air-conditioning apparatus switches each of a plurality of use-side heat exchangers to a cooling operation or a heating operation in accordance with a control command to perform a cooling and heating simultaneous operation. The refrigerant is caused to flow through the heat source device-side heat exchanger depending on a ratio of a total cooling capacity and a total heating capacity of the plurality of use-side heat exchangers. The heat-medium flow control device controls the flow rate of the heat medium supplied to the heat source device-side heat exchanger based on a difference between the total cooling capacity and the total heating capacity of the plurality of use-side heat exchangers and a total operation capacity of the heat source device-side heat exchanger.