The present invention relates to a method and system of inspecting a product, including extracting defects from the product, classifying the defects on the basis of information about the extracted defects representing the analogy of the defects, extracting the feature data of the defects on the basis of the result of defect classification, and feeding back the feature data of the extracted defects for inspection. The method and system is characterized in that the extracted feature data of the defects is fed back for inspecting the product. The present invention also relates to a method of manufacturing a semiconductor electric or electronic device, including extracting defects from the semiconductor electric or electronic device, classifying the defects on the basis of information about the extracted defects representing the analogy of the defects, extracting the feature data of the defects on the basis of the result of defect classification, and feeding back the feature data of the extracted defects to an apparatus for manufacturing the semiconductor electric or electronic device.