An air-conditioning apparatus, comprising: a control device configured to centrally control the operation of the air-conditioning apparatus, a refrigerant circuit that is configured to circulate heat source side refrigerant through a compressor, a first refrigerant channel switching device, a heat source side heat exchanger, a plurality of expansion devices, and refrigerant side flow channels of a plurality of intermediate heat exchangers, which are connected by refrigerant pipes; a heat medium circuit that is configured to circulate heat medium through a pump, a plurality of use side heat exchangers, and heat medium side flow channels of the plurality of intermediate heat exchangers, which are connected by heat medium transport pipes; and a blower device corresponding to each of the use side heat exchangers, wherein the air-conditioning apparatus is configured to exchange heat between the heat source side refrigerant and the heat medium in the intermediate heat exchangers, and to perform a cooling operation mode in which at least one of the plurality of use side heat exchangers performs cooling operation using heat medium cooled by the intermediate heat exchangers, a heating operation mode in which at least one of the plurality of use side heat exchangers performs heating operation using heat medium heated by the intermediate heat exchangers, and a non-operating mode in which the compressor, the pump, each of the use side heat exchangers, and each of the blower devices are stopped, wherein the control device is configured: to start the blower device of the indoor unit from which a start command is originated, when starting the cooling operation mode from the non-operating mode, and to operate the blower device of the indoor unit from which a start command is originated after the temperature of the heat medium becomes equal to or greater than a preconfigured temperature, when starting the heating operation mode from the non-operating mode, the air-conditioning apparatus characterized in that the control device is further configured: to gradually increase the flow rate to the preconfigured flow rate after first being set to a flow rate being very lower than a preconfigured flow rate and then being set to a flow rate being lower than the preconfigured flow rate, when operating the blower device of the indoor unit from which the start command is originated. a control device configured to centrally control the operation of the air-conditioning apparatus, a refrigerant circuit that is configured to circulate heat source side refrigerant through a compressor, a first refrigerant channel switching device, a heat source side heat exchanger, a plurality of expansion devices, and refrigerant side flow channels of a plurality of intermediate heat exchangers, which are connected by refrigerant pipes; a heat medium circuit that is configured to circulate heat medium through a pump, a plurality of use side heat exchangers, and heat medium side flow channels of the plurality of intermediate heat exchangers, which are connected by heat medium transport pipes; and a blower device corresponding to each of the use side heat exchangers, wherein the air-conditioning apparatus is configured to exchange heat between the heat source side refrigerant and the heat medium in the intermediate heat exchangers, and to perform a cooling operation mode in which at least one of the plurality of use side heat exchangers performs cooling operation using heat medium cooled by the intermediate heat exchangers, a heating operation mode in which at least one of the plurality of use side heat exchangers performs heating operation using heat medium heated by the intermediate heat exchangers, and a non-operating mode in which the compressor, the pump, each of the use side heat exchangers, and each of the blower devices are stopped, a cooling operation mode in which at least one of the plurality of use side heat exchangers performs cooling operation using heat medium cooled by the intermediate heat exchangers, a heating operation mode in which at least one of the plurality of use side heat exchangers performs heating operation using heat medium heated by the intermediate heat exchangers, and a non-operating mode in which the compressor, the pump, each of the use side heat exchangers, and each of the blower devices are stopped, wherein the control device is configured: to start the blower device of the indoor unit from which a start command is originated, when starting the cooling operation mode from the non-operating mode, and to operate the blower device of the indoor unit from which a start command is originated after the temperature of the heat medium becomes equal to or greater than a preconfigured temperature, when starting the heating operation mode from the non-operating mode, the air-conditioning apparatus to start the blower device of the indoor unit from which a start command is originated, when starting the cooling operation mode from the non-operating mode, and to operate the blower device of the indoor unit from which a start command is originated after the temperature of the heat medium becomes equal to or greater than a preconfigured temperature, when starting the heating operation mode from the non-operating mode, the air-conditioning apparatus characterized in that the control device is further configured: to gradually increase the flow rate to the preconfigured flow rate after first being set to a flow rate being very lower than a preconfigured flow rate and then being set to a flow rate being lower than the preconfigured flow rate, when operating the blower device of the indoor unit from which the start command is originated.