PURPOSE: To obtain a motor speed commander having high operation efficiency by providing means for adding/subtracting a predetermined number to/from the integer part of a previous speed command value when a decision means decides that an operating period matches with a count and then clearing a counting means.

CONSTITUTION: The motor speed commander comprises a circuit 1 for detecting the variation of speed command value for a motor, a circuit 2 for comparing the detected variation with a preset reference value, a circuit 3 for adding/ subtracting the variation to/from the speed command value based on the comparison results, a circuit 4 for calculating the reciprocal of the variation as an operation period if the variation is lower than the reference value, a circuit 5 for counting each control period, a circuit 6 for deciding whether the count of the counting circuit 5 matches with the operation period of the operation period calculating circuit 4, and operating circuit 7 for adding/subtracting 1 to/from the integer part of previous speed command value upon decision of matching and then clearing the counting circuit 5.