An air-conditioning apparatus including at least one indoor unit (200a, 200b), and outdoor unit and a main pipe that connects the at least one indoor unit (200a, 200b) and the outdoor unit such that a refrigerant is adapted to circulate therethrough, the at least one indoor unit (200a, 200b) comprising: - an indoor heat exchanger (4a, 4b); and - a first flow control valve (5a, 5b) configured to control a flow rate of the refrigerant entering the indoor heat exchanger (4a, 4b); and the outdoor unit comprising: - an injection compressor including an injection port allowing part of the refrigerant circulating to be injected therethrough into the refrigerant undergoing compression; - a refrigerant flow switching device configured to switch between a cooling operation and a heating operation; - an outdoor heat exchanger (9a, 9b) including a plurality of outdoor heat exchangers (9a, 9b) connected in parallel; - a first bypass pipe having a first end connected between the injection compressor and the refrigerant flow switching device and a second end connected to a first one of inlet and outlet sides of the plurality of outdoor heat exchangers (9a, 9b); and - a first flow switching device configured to switch a flow of the refrigerant to the main pipe or the first bypass pipe, characterized in that the outdoor unit further comprises: - a first bypass flow control valve provided to the first bypass pipe and configured to control a flow rate of the refrigerant; - a second bypass pipe having a first end connected to the injection port or a pipe connected to the injection port and a second end connected to a second one of the inlet and outlet sides of the plurality of outdoor heat exchangers (9a, 9b); - and - a second flow switching device configured to switch the flow of the refrigerant to the main pipe or the second bypass pipe, - wherein in a defrosting operation of removing frost in any of the plurality of outdoor heat exchangers (9a, 9b), - the first flow switching device is adapted to cause part of the refrigerant discharged from the injection compressor to flow through the first bypass pipe and decompress thereof by the first bypass flow control valve, and the refrigerant is adapted to be supplied to the outdoor heat exchanger (9a, 9b) comprising the plurality of outdoor heat exchangers (9a, 9b) and targeted for defrosting, and the second flow switching device is adapted to cause part of the refrigerant supplied to the outdoor heat exchanger (9a, 9b) targeted for defrosting to enter the second bypass pipe. - an indoor heat exchanger (4a, 4b); and - a first flow control valve (5a, 5b) configured to control a flow rate of the refrigerant entering the indoor heat exchanger (4a, 4b); and - an injection compressor including an injection port allowing part of the refrigerant circulating to be injected therethrough into the refrigerant undergoing compression; - a refrigerant flow switching device configured to switch between a cooling operation and a heating operation; - an outdoor heat exchanger (9a, 9b) including a plurality of outdoor heat exchangers (9a, 9b) connected in parallel; - a first bypass pipe having a first end connected between the injection compressor and the refrigerant flow switching device and a second end connected to a first one of inlet and outlet sides of the plurality of outdoor heat exchangers (9a, 9b); and - a first flow switching device configured to switch a flow of the refrigerant to the main pipe or the first bypass pipe, characterized in that the outdoor unit further comprises: - a first bypass flow control valve provided to the first bypass pipe and configured to control a flow rate of the refrigerant; - a second bypass pipe having a first end connected to the injection port or a pipe connected to the injection port and a second end connected to a second one of the inlet and outlet sides of the plurality of outdoor heat exchangers (9a, 9b); - and - a second flow switching device configured to switch the flow of the refrigerant to the main pipe or the second bypass pipe, - wherein in a defrosting operation of removing frost in any of the plurality of outdoor heat exchangers (9a, 9b), - the first flow switching device is adapted to cause part of the refrigerant discharged from the injection compressor to flow through the first bypass pipe and decompress thereof by the first bypass flow control valve, and the refrigerant is adapted to be supplied to the outdoor heat exchanger (9a, 9b) comprising the plurality of outdoor heat exchangers (9a, 9b) and targeted for defrosting, and