An air-conditioning apparatus comprising: a refrigeration cycle in which a compressor that compresses a low pressure refrigerant and discharges a high pressure refrigerant, a first heat exchanger that exchanges heat between the refrigerant and an external fluid, first expansion devices that depressurize the refrigerant, and one or more second heat exchangers that exchange heat between the refrigerant and an external fluid are connected by refrigerant pipes; an injection pipe that circulates the refrigerant split off from a refrigerant flow path through which the refrigerant that has radiated in the first heat exchanger or the one or more second heat exchangers flows; a first refrigerant branching portion that divides the refrigerant from the refrigerant flow path in the case where the refrigerant is flowing from the first heat exchanger to the first expansion devices; a second refrigerant branching portion that divides the refrigerant from the refrigerant flow path in the case where the refrigerant is flowing from the first expansion devices to the first heat exchanger; a branching pipe that connects the first refrigerant branching portion and the second refrigerant branching portion, with the injection pipe connected thereto; and a controller that carries out driving control of the compressor; wherein the compressor includes an aperture unit in part of a compression chamber included inside a hermetically sealed container, the injection pipe is connected to the aperture unit via a second expansion device that depressurizes the refrigerant flowing thereinto, and the controller controls an injection quantity of refrigerant introduced into the compression chamber from the injection pipe via the aperture unit by controlling an opening degree of the second expansion device. a refrigeration cycle in which a compressor that compresses a low pressure refrigerant and discharges a high pressure refrigerant, a first heat exchanger that exchanges heat between the refrigerant and an external fluid, first expansion devices that depressurize the refrigerant, and one or more second heat exchangers that exchange heat between the refrigerant and an external fluid are connected by refrigerant pipes; an injection pipe that circulates the refrigerant split off from a refrigerant flow path through which the refrigerant that has radiated in the first heat exchanger or the one or more second heat exchangers flows; a first refrigerant branching portion that divides the refrigerant from the refrigerant flow path in the case where the refrigerant is flowing from the first heat exchanger to the first expansion devices; a second refrigerant branching portion that divides the refrigerant from the refrigerant flow path in the case where the refrigerant is flowing from the first expansion devices to the first heat exchanger; a branching pipe that connects the first refrigerant branching portion and the second refrigerant branching portion, with the injection pipe connected thereto; and a controller that carries out driving control of the compressor; wherein the compressor includes an aperture unit in part of a compression chamber included inside a hermetically sealed container, the injection pipe is connected to the aperture unit via a second expansion device that depressurizes the refrigerant flowing thereinto, and the controller controls an injection quantity of refrigerant introduced into the compression chamber from the injection pipe via the aperture unit by controlling an opening degree of the second expansion device.