1. A defect classification/inspection system comprising: a defect extracting unit for picking up an image of an inspection object and comparing the image with a reference image having no defect, thereby extracting an image of a defect part; a characteristics extracting unit for extracting and digitizing the characteristics quantity of the image of the defect part extracted by the defect extracting unit; a database preparing unit including defect classifying means for grouping defects having similar characteristics on the basis of the characteristics information digitized by the characteristics extracting unit, classification code providing means for providing a classification code to the defects grouped by the defect classifying means, storage means for saving the characteristics information of the defects grouped by the defect classifying means together with the classification code provided by the classification code providing means as a database, and selecting/designating means for selecting and designating a defect group for which a database of a next hierarchical level is to be prepared, from the respective defect groups having the grouped defects and having the classification code provided thereto, the database preparing unit regrouping defects having similar characteristics by the defect classifying means on the basis of the characteristics information digitized by the characteristics extracting means with respect to the defects belonging to the defect group selected and designated by the selecting/designating means, and preparing a database in which the defects of the inspection object are hierarchically classified; and a classification executing unit for hierarchically classifying the defects of the inspection object with reference to the database provided by the database preparing unit on the basis of the digitized characteristics information extracted by the characteristics extracting unit from the image of the defect part of the inspection object extracted by the defect extracting unit.