PURPOSE: To make it possible to change the current command value in response to the fluctuation in motor load before the variation in motor speed and to control the fluctuation in speed caused by that in load by employing either constitution that a limiter outputs by changing over either of set values in steady- and unsteady-state torque setting means.

CONSTITUTION: The speed control device is provided with a limiter 20 for limiting the current command value output from a speed control means 13. It is also provided with an steady-state torque setting means 23 for setting the output from the limiter 20 to a torque value corresponding to the steady-state load of a motor 4; and an unsteady-state torque setting means 24 for setting the output to a torque value corresponding to the unsteady-state load of the motor 4. In addition the control device is provided with a load state detection means for judging whether the load of the motor 4 is in steady state or unsteady state; and a switching means 22 which switches the steady-state torque setting means 23 and the unsteady-state torque setting means 24 according to the detected state of the load. This makes possible controlling the fluctuation in motor speed in response to that in load without adding a compensator, which l is expensive and complicates circuits.