PURPOSE: To enable high accuracy positioning by recognizing positional coordinates of a total pad of a circuit board and a total lead of an electronic component and positioning so that the sum of a square of the amount of positional deviation of each mating lead and a pad.

CONSTITUTION: An attempt is made to recognize the central positional coordinates (PA1x, PA1y) of each pad PA1,...PDn of a circuit board 1, and determine an X axial central line 3 and a Y axial central line 4 of the circuit board 1 respectively. A further attempt is made to determine an X axial central line 6 and a Y axial central line 7 of an electronic component 5 as well. Furthermore, an another attempt is made to determine the correction values of X, Y and θ so that the Y axial central line 3 and the Y axial central line 4 of the circuit board 1 and the X axial central line 6 and the Y axial central line 7 of the electronic component 5 may overlap each other. A further attempt is made to determine the correction values of X, Y, and θ again so that the sum of a square of the deviation of the X axis Zijx and the deviation of the Y axis Zijy in the center of the lead against the center of the pads may be minimized, thereby positioning the electronic component to the circuit board 1. Therefore, it is possible to carry out high accuracy positioning.