PURPOSE: To accurately aligning a true position coordinate system of an integrated circuit chip with an optical coordinate system by detecting the deviation in position between the optical coordinate system of a laser beam optical means and one coordinate system of the integrated circuit chip from the detected quantity appearing on pulling-out electrodes.

CONSTITUTION: A laser beam 11a is scanned on a photodiode 12a and probing needles 18a and 18b are brought into contact with the pulling-out electrodes 13a and 13b and the electric potential difference V thereof is measured. At this time, a CPU 15 executes feedback control of a laser beam deflector 11c so that the electric potential difference V becomes maximum and the laser beam 11a having about 5μm irradiation diameter is coincident with a slit 19 having about 5μm gap. Here, aligning in the X-axial direction is executed one- dimensionally and further, aligning in the Y-axial direction is executed two- dimensionally by using the other photodiode 12a provided in the IC chip, for instance. By this method, the position coordinate systems X and Y of a semiconductor wafer 14 can be aligned with the optical coordinate systems x and y of the laser beam optical means with high accuracy.