A positioning device includes a driver which moves a positioning object and a sensor which measures the distance to the positioning object in a non-contacting manner and outputs a detection signal if the positioning object is detected only in a length measuring area within a predetermined range from any detection position, shaft controller which stops the driver by detecting the detection signal from the sensor and automatically correcting for an overshoot amount between the stop position and any detection position, when the driver moves the positioning object and the sensor, and the positioning controller that stores the coordinate value after the automatic correction by the shaft controller and that performs the positioning based on the reference coordinate value.