PURPOSE: To conduct the processing of an outer layer drilling origin at the optimum position on a multi-layer print wiring board.

CONSTITUTION: X rays are irradiated onto a multi-layer print wiring board 3 set on a table 6 by means of an X ray generating source 9. At the multi-layer print wiring board 3, each layer reference pattern is possessed at every each layer of inner layers so as to prevent interference, and these reference patterns are received at an X ray receiving portion built inside the table 6, and outputted to a controller 12. At the controller 12, displacement from design position coordinates is measured by conducting the operation processing of light receiving reference patterns, and the correction amounts of respective layer surfaces in X, Y, Z directions are calculated, and processing data is outputted, and the positioning of a spindle 7 is conducted, and drilling origin processing is conducted at the multi-layer print wiring board.