A compressor comprising: a rotating shaft that is configured to rotate around an axis; a first impeller and a second impeller that are configured to rotate along with the rotating shaft to compress and discharge an intake working fluid; a casing that is configured to cover the rotating shaft, the first impeller and the second impeller is provided with a diffuser for guiding the working fluid discharged from the first impeller to an outside in a radial direction of the rotating shaft; a heat exchanger that is configured to cool at least a portion of the working fluid compressed by the first impeller; a cooling fluid supplying unit that is configured to supply the working fluid cooled by the heat exchanger into the casing as a cooling fluid for cooling a cooling object part disposed in the casing; a cooling fluid circulating unit that is configured to discharge the cooling fluid that has passed through the cooling object part to an outside of the casing, and supply the discharged cooling fluid downstream of an outlet of the first impeller and upstream of the diffuser; a motor that is disposed in the casing, is configured to drive the rotating shaft to rotate around the axis, and has a motor rotor and a stator; a detecting unit that is configured to detect temperature of a coil of the stator of the motor; and a flow rate adjusting unit that is configured to adjust a flow rate of the cooling fluid supplied into the casing based on a determination result in the detecting unit, wherein the second impeller is configured to compress the working fluid compressed by the first impeller, and is fixed to the rotating shaft so as to face a direction opposite to the first impeller with respect to an axial direction in which the axis extends, wherein the motor is disposed between the first impeller and the second impeller, wherein the cooling fluid supplied into the casing by the cooling fluid supplying unit cools the motor as the cooling object part, wherein the motor rotor has a plurality of permanent magnets, wherein the stator covers the motor rotor, wherein the casing is formed so that the cooling fluid pass through a gap between the motor rotor and the stator so as to go from the first impeller to the second impeller in the axial direction (Da), wherein the casing has nozzles that are connected to the diffuser and are disposed at intervals in a circumferential direction around the axis of the rotating shaft, and wherein the cooling fluid circulating unit is configured to supply the cooling fluid, which is discharged to the outside of the casing after passing through the gap, to the diffuser through the plurality of nozzles. a rotating shaft that is configured to rotate around an axis; a first impeller and a second impeller that are configured to rotate along with the rotating shaft to compress and discharge an intake working fluid; a casing that is configured to cover the rotating shaft, the first impeller and the second impeller is provided with a diffuser for guiding the working fluid discharged from the first impeller to an outside in a radial direction of the rotating shaft; a heat exchanger that is configured to cool at least a portion of the working fluid compressed by the first impeller; a cooling fluid supplying unit that is configured to supply the working fluid cooled by the heat exchanger into the casing as a cooling fluid for cooling a cooling object part disposed in the casing; a cooling fluid circulating unit that is configured to discharge the cooling fluid that has passed through the cooling object part to an outside of the casing, and supply the discharged cooling fluid downstream of an outlet of the first impeller and upstream of the diffuser; a motor that is disposed in the casing, is configured to drive the rotating shaft to rotate around the axis, and has a motor rotor and a stator; a detecting unit that is configured to detect temperature of a coil of the stator of the motor; and a flow rate adjusting unit that is configured to adjust a flow rate of the cooling fluid supplied into the casing based on a determination result in the detecting unit, wherein the second impeller is configured to compress the working fluid compressed by the first impeller, and is fixed to the rotating shaft so as to face a direction opposite to the first impeller with respect to an axial direction in which the axis extends, wherein the motor is disposed between the first impeller and the second impeller, wherein the cooling fluid supplied into the casing by the cooling fluid supplying unit cools the motor as the cooling object part, wherein the motor rotor has a plurality of permanent magnets, wherein the stator covers the motor rotor, wherein the casing is formed so that the cooling fluid pass through a gap between the motor rotor and the stator so as to go from the first impeller to the second impeller in the axial direction (Da), wherein the casing has nozzles that are connected to the diffuser and are disposed at intervals in a circumferential direction around the axis of the rotating shaft, and wherein the cooling fluid circulating unit is configured to supply the cooling fluid, which is discharged to the outside of the casing after passing through the gap, to the diffuser through the plurality of nozzles.