Patent ID: 8892494

Claim:
A defect classification apparatus which classifies, based on attribute data of defects obtained from image data obtained by taking an image of a test object, the defects into a group of first classes, and classifies, based on the attribute data of the defects classified into the group of first classes, the defects into a group of second classes, comprising: a storage unit which stores, for each of the defects, classification answer information which identifies the group of second classes to which the each of the defects is to be classified; and a control unit, the control unit performing the processings of: classifying the defects into the group of second classes based on a value obtained by multiplying a likelihood value determined for each of the group of first classes, each of the group of second classes, and each type of the attribute data by a value of a weight coefficient determined for the each of the group of first classes, the each of the group of second classes, and the each type of the attribute data; comparing the second classes to which the defects are classified and the second class to which the defects are to be classified, which is identified by the classification answer information, to calculate classification performance in each combination of the first classes and the second classes and in the second classes to which the defects are classified from all the first classes; and outputting classification performance information which associates the calculated classification performance with the each combination of the first classes and the second classes, and the second classes to which the defects are classified from all the first classes, to an output unit.