Motor-driven turbo compressor

To provide a motor-driven turbo compressor that has high durability and is capable of surely improving efficiency of a refrigeration circuit. In the compressor of the present invention, an intermediate pressure port 31 through which a first discharge chamber 25 and a first chamber 29a communicate with each other is formed in a front housing 11. In the front housing 11, an injection port 43 through which a receiver 103 and a second chamber 29b communicate with each other is formed. An intermediate pressure refrigerant discharged to the first discharge chamber 25 flows into the first chamber 29a through an intermediate pressure port 31. An injection refrigerant separated by the receiver 103 flows into the second chamber 29b. In the compressor, it is possible to cool an electric motor 5 with the intermediate pressure refrigerant and the injection refrigerant. The intermediate pressure refrigerant and the injection refrigerant circulate through a second suction port 37 as a mixed refrigerant. Therefore, in the compressor, it is possible to suitably suppress a temperature rise of the mixed refrigerant when the mixed refrigerant flows into a second impeller chamber 19.