PURPOSE: To position a pellet division on a wafer and a photo-mask with high precision by forming the wafer having structure having target marks at the positions of a longest distance on a diagonal line tying the corner sections of the pellet division.

CONSTITUTION: A wafer having the structure having target marks 6a, 6b at the positions of the longest distance on a diagonal line tying the corner sections 5a, 5b of a pellet division 3 is formed. An XY table or a photo-mask is moved by a fixed quantity in the XY directions so that an external corner section 7a in one target pattern 6a is positioned at a position where it is brought into contact with the photo-mask in the pellet division on the wafer. The quantity of displacement (d) between each corner section 7b in the other respective target pattern 6b is detected mechanically. The pellet division is shifted by a fixed quantity in the θ-direction centering around the corner section 7a by the quantity of displacement (d), thus resulting in d=0.