In this air conditioning device, a heat source machine and an indoor machine including an indoor-side flow rate control device and an indoor-side heat exchanger are coupled to one another by means of refrigerant piping. The heat source machine is provided with: an outdoor-side heat exchanging unit including a plurality of outdoor-side heat exchangers coupled in parallel with one another to a compressor; first heat-source-side bypass piping one end of which is coupled to a discharge side of the compressor and the other end of which is coupled to each of the plurality of outdoor-side heat exchangers; a first pressure reducing device which is provided in the first heat-source-side bypass piping and which reduces the pressure of refrigerant discharged from the compressor; a bypass opening and closing unit which is provided in the first heat-source-side bypass piping and which either allows refrigerant discharged from the compressor to pass through to each of the outdoor-side heat exchangers, or shuts off the flow of refrigerant to each of the outdoor-side heat exchangers; second heat-source-side bypass piping which couples the plurality of outdoor-side heat exchangers to one another, and which causes refrigerant that has flowed out from one outdoor-side heat exchanger to flow into another outdoor-side heat exchanger; and a second pressure reducing device which is provided in the second heat-source-side bypass piping and which reduces the pressure of refrigerant passing through the second heat-source-side bypass piping.