PURPOSE: To drill with high accuracy circuit patterns on a multilayer substrate by comparing measurement results obtained before and after laminating four marks forming a min. rectangle surrounding a machining position with each other and by correcting the machining position specified by programs based on the comparison result.

CONSTITUTION: A plurality of measuring marks P11 to P76 are placed in matrix shape at predetermined intervals on a prelaminated printed substrate 1. The distance from the reference position to each mark P11 to P76 is measured. Next, in machining the laminated multilayered substrate, the distance from the reference position to each mark P11 to P76 is again measured to compare measurement results obtained before and after laminating four marks, P34, P35, P44, and P45, forming tire min. rectangle surrounding the machining position H1 with each other. The machining position H1 specified by programs is corrected to the actual machining position based on the comparison result.