A multi-stage electric centrifugal compressor and a supercharging system for an internal combustion engine with a driving unit of a rotational shaft that can be readily controlled when a single-shaft and two-stage centrifugal compressor is employed is provided. A multi-stage electric centrifugal compressor includes: an electric motor; and a pair of centrifugal compressors coupled to either side of the electric motor, the pair of centrifugal compressors comprising a low-pressure stage compressor and a high-pressure stage compressor connected in series. The low-pressure stage compressor and the high-pressure stage compressor are formed to have different pressure ratios from each other.