A control device for a plurality of rotating electrical machines has a single current control device with an inverter, gate driver, and a motor controller, which supplies a control current to each rotating electrical machine allowing rotation control in response to the rotational phase of the rotor. In this control device, the current control device determines the control current of each rotating electrical machine based on the target torques and rotational angular velocities of all rotating electrical machines, and supplies a composite current obtained by combining the determined control currents for each rotating electrical machine to all rotating electrical machine. In this control device for a plurality of rotating electrical machines, the required voltage does not exceed the voltage of the power source and the peak value of the composite current does not exceed the permitted range of the inverter.