PURPOSE: To surely detect board installation holes, substrate separation holes, etc., through image processing and calculate coordinate data in the inspection range where the above-described part is excluded, because the inspection range is set by excluding the board installation holes, board separation holes, etc., which can be erroneously recognized as defect from the inspection range, in inspecting patterns on the printed board, etc.

CONSTITUTION: A shadow part is formed by the transparent lighting at a hole part on an uninspected article, and the image is digital-expressed through binary expression. The uninspected part is surely detected by the contraction processing and magnification processing for the image, and the coordinate data in the inspection range where the uninspected part is excluded is calculated.