To provide a generator motor coupled integrally with a control unit capable of exchanging heat sufficiently between a radiating member and air, and cooling control elements effectively without increasing air flow rate.

This generator motor is coupled integrally with the control unit, and comprises a stator 30 and a rotor 25 contained in a housing 16 in which an exhaust outlet 18a is formed; the control unit 65 that, mounted in a donut-shaped casing 50 fixed to the housing, includes control elements 53 and the like that convert AC to DC; a hollow disk-shaped radiating member 70 on one side surface of which a plurality of radiating fins 73 are formed, and on the other side of which the control elements are mounted; and a cover 80 that covers the radiating fins and on the outside circumferential portion of which a plurality of inlets 85 are formed. The control element 53 and the like are cooled by making air sucked from the inlets 85 flow in the centripetal direction of the radiating member 70, pass through hollow holes 72, and discharged form an outlet 18a.