Abstract: In a robot, an object to be controlled, e.g., a working tool mounted on a robot wrist is purposively moved in accordance with data taught in advance. In case the object is encountered with a shaping or mounting error, a correction is accordingly required. This requirement makes it necessary to generate a desired error vector so that the robot may be moved while correcting the taught data in accordance with that vector. The object can be moved in a manual mode with its location being fixed while changing its position. In case, however, the object is accompanied by the shaping error or the like, not only the position but the location is changed following the position changing operation. The error vector can be arithmetically determined from data concerning such locational change.