ELECTRIC MOTOR AND COMPRESSOR USING SAME

To suppress undesirable phenomena such as increased oil drain brought about by adjusting the weight of a balance weight. An electric motor comprises a rotor (10), a stator, and a balance weight (80). The rotor (10) rotates about a rotational axis (RA). The stator magnetically interacts with the rotor (10). The balance weight (80) is attached to the rotor (10). The balance weight (80) has a rotor contact surface (81) in contact with the rotor (10). A concave part (82) indented in the extending direction of the rotational axis (RA) is provided in the vicinity of the rotor contact surface (81) of the balance weight (80). The concave part (82) is enclosed by the rotor contact surface (81). Inner surfaces of the concave part (82) and the rotor (10) forming an enclosed space.