PURPOSE: To easily and surely decide the position of a positioned object by stopping a mobile means to perform a positioning action after detection of the coincidence between the distance measured between both detection parts and the distance set previously between these detection parts.

CONSTITUTION: A detection part defined on the surface of a positioned object 7 such as a dry cell, etc., is detected by a sensor means 3 like a photoelectric tube provided in an area, and the detection and detected signals are transmitted. Based on these signals, a signal is transmitted to a controller 5 of a mobile means 6 like a motor, etc., for control of the means 6 as long as the coincidence is secured between the distance set between both detection parts defined on the object 7 and the value set previously. Thus the means 6 is stopped and the object 7 is positioned. In such a way of positioning, the means 3 can surely sense a detection part out of a design of a container, etc. Furthermore there is no requirement to print a special resist mark, etc.