To easily and correctly perform the very short distance moving of a slide even by an unskilled worker by instructing the moving amount of the slide by a moving amount command input means, and moving the slide to a target position, operating a flow rate control servo valve controlling the expansion and contraction speeds of a cylinder while detecting the position of the slide.

The manual purser 20 of the moving amount command input means 10 is rotated by a prescribed angle by a worker. The angle is converted into the number of pulses by a pulse detecting means 21, and is inputted to a command output effective judgment means 23. Only during a slow speed operation switch 11 or a setting up inching selection switch 12 has been inputted, a position command is outputted to the flow rate control servo valve 14 through a servo amplifier 15 by the effective judgment means 23. The cylinder 4 is vertically driven by a designated moving amount at a prescribed slow speed by the flow rate control servo valve 14. The moving amount is detected by a linear sensor 6, an error signal is feeded back to a servo amplifier 15, and an error is corrected.