A motor-operated compressor is provided and includes an orbiting scroll and a rear housing supporting a rear surface of the orbiting scroll. The rear housing includes a discharge space communicating with a discharge port of the orbiting scroll formed at a central portion of a surface facing the orbiting scroll, an oil separation space formed at one side of the discharge space to communicate with the discharge space, and an oil storage space formed at an edge portion of the surface facing the orbiting scroll. An oil return passage is provided between the oil separation space and the oil storage space, so as to guide oil separated in the oil separation space to the oil storage space. Accordingly, a space for storing oil separated from a discharged refrigerant is sufficiently secured while allowing the rear housing defining the oil storage space to be easily fabricated.