Abstract: A positioning device includes moving means (2) for relatively moving a positioning object (21) and length measuring means (8) for measuring the distance to the positioning object (21) in non-contact manner and outputting a detection signal if the positioning object (21) is detected only in a length measuring area within a predetermined range from any detection position, shaft control means for stopping the moving means (2) by detecting the detection signal from the length measuring means (8) and automatically correcting for an overshoot amount between the stop position and any detection position, when the moving means (2) relatively moves the positioning object (21) and the length measuring means (8), and positioning control means (11) for storing the coordinate value after the automatic correction by the shaft control means and performing the positioning based on the reference coordinate value.