The control device for an electric motor according to this application provides a battery voltage detecting part for detecting a battery voltage at the time of driving a motor driven by a battery, and a minimum voltage holding part for keeping the battery voltage above the predetermined voltage by reducing the consumption current of the electric motor when the battery voltage detected by the battery voltage detecting part falls below a predetermined voltage during driving of the electric motor, so that it is possible to suppress a reduction in battery voltage during driving at low cost, and it is possible to keep the battery voltage above the predetermined voltage.