An air-conditioning apparatus, including a compressor, a refrigerant flow switching device, a heat source side heat exchanger, a first expansion device, and an intermediate heat exchanger connected via refrigerant pipes, that constitutes a refrigerant circuit, and a pump, the intermediate heat exchanger, and a use side heat exchanger connected via pipes, that constitutes a heat medium circuit, the air-conditioning apparatus comprising: a second expansion device provided on an upstream side of the heat source side heat exchanger and on a downstream side of the first expansion device during a heating operation; an accumulator configured to accumulate excess refrigerant provided on an upstream side of the compressor; a suction injection pipe, having a third expansion device provided thereto, and having one end connected on an upstream side of the third expansion device, and another end connected to a flow channel between a suction side of the compressor and the accumulator; a discharge refrigerant temperature detector configured to detect a discharge refrigerant temperature of the compressor; and a suction pressure detection device configured to detect a refrigerant pressure suctioned into the compressor; a medium pressure detector configured to detect a refrigerant pressure or a refrigerant saturation temperature on an upstream side of the second expansion device during the heating operation and on a downstream side of the first expansion device or the intermediate heat exchanger; a controller configured to control an opening degree of the second expansion device based on a detection result from the medium pressure detector and control an opening degree of the third expansion device based on detection results from the discharge refrigerant temperature detector, the medium pressure detector and the suction pressure detection device; wherein, inside the refrigerant pipes, R32 or a refrigerant mixture with an R32 mass ratio of 62% or greater is circulated as refrigerant, the controller, computes a quality of refrigerant suctioned into the compressor based on the opening degree of the second expansion device, the opening degree of the third expansion device and the detection results from the medium pressure detector and the suction pressure detection device, when the quality becomes less than a predetermined value in a state in which the opening degree of the third expansion device is controlled to a first opening degree based on the detection result from the discharge refrigerant temperature detector, reduces the opening degree of the third expansion device to a second opening degree which is less than the first opening degree, and causes refrigerant having the quality equal to or greater than 0.9 and less than or equal to 0.99 to be suctioned into the compressor. a second expansion device provided on an upstream side of the heat source side heat exchanger and on a downstream side of the first expansion device during a heating operation; an accumulator configured to accumulate excess refrigerant provided on an upstream side of the compressor; a suction injection pipe, having a third expansion device provided thereto, and having one end connected on an upstream side of the third expansion device, and another end connected to a flow channel between a suction side of the compressor and the accumulator; a discharge refrigerant temperature detector configured to detect a discharge refrigerant temperature of the compressor; and a suction pressure detection device configured to detect a refrigerant pressure suctioned into the compressor; a medium pressure detector configured to detect a refrigerant pressure or a refrigerant saturation temperature on an upstream side of the second expansion device during the heating operation and on a downstream side of the first expansion device or the intermediate heat exchanger; a controller configured to control an opening degree of the second expansion device based on a detection result from the medium pressure detector and control an opening degree of the third expansion device based on detection results from the discharge refrigerant temperature detector, the medium pressure detector and the suction pressure detection device; wherein, inside the refrigerant pipes, R32 or a refrigerant mixture with an R32 mass ratio of 62% or greater is circulated as refrigerant, the controller, computes a quality of refrigerant suctioned into the compressor based on the opening degree of the second expansion device, the opening degree of the third expansion device and the detection results from the medium pressure detector and the suction pressure detection device, when the quality becomes less than a predetermined value in a state in which the opening degree of the third expansion device is controlled to a first opening degree based on the detection result from the discharge refrigerant temperature detector, reduces the opening degree of the third expansion device to a second opening degree which is less than the first opening degree, and causes refrigerant having the quality equal to or greater than 0.9 and less than or equal to 0.99 to be suctioned into the compressor.