A controller of a rotating electric machine for a vehicle has a magnetic field electric current command arithmetic device for commanding a magnetic field electric current by the command of a torque and electric power command arithmetic device, an electric power converter functioning as a rectifier or an inverter, and a magnetic field electric current command restraining device for restraining a three-phase line electric current by restraining and controlling an output of the magnetic field electric current command arithmetic device when the rotating electric machine functions as an electric generator.