There are provided with a motor rotor (22) fixed to a turbine shaft (12) and rotating together with the turbine shaft, a motor stator (24) surrounding the motor rotor and fixed within a bearing housing (16), an inverted (26) converting a dc power into an ac power, and an inverter controller (28) controlling a frequency and a voltage of the ac power by the inverter. The inverter and the inverter controller are accommodated in a driver container (29), and are coupled to a compressor housing (20) by an insulating coupling member (30).
