A control device for a rotating machine driving an elevator suppresses increases in the moving time of the elevator while securing control and stability in accordance with moving direction and load of a car of the elevator. A control device for controlling speed of the rotating machine without using a speed sensor includes a speed command signal generator for generating a rotational speed command for the rotating machine; and a speed sensor-less controller for controlling a voltage applied to the rotating machine without using a speed sensor, based on the rotational speed command from the speed command signal generator. In the control device, the speed command signal generator changes an acceleration running curve in a deceleration interval in accordance with the moving direction and the load of the car of the elevator to generate the rotational speed command.