PURPOSE: To sufficiently utilize original high response of a stepping cylinder in the case of controlling a rod position of the cylinder according to a position type control command.

CONSTITUTION: A cylinder controller 2 in which a position type control command ΔS is applied, generates a drive pulse train to be generated from a pules generator 22 in response thereto, applies it to a drive circuit 80 for a stepping cylinder driving pulse motor, and drives the motor. In this case, the generator 22 generates a damping pulse for suppressing damping after the generation of the pulse train is finished, increases, in addition thereto, a period of several pulses before the generation of the pulse train is finished, and so regulates the magnitude of the damping that a damping effect by the pulse is enhanced higher. The generator 22 examines a rotating direction when generation of the pulse train is started and a direction of the damping to be recognized by a signal (a) indicating a damping behavior, delays the start of the generation if both coincide, and prevents generation of a stepout. Further, these operations are conducted for a pulse motor having a mechanical damper and mechanically suppressing a damping.