Disclosed is a technique wherein an object that requires adjustment in order to increase the reliability of automatic classification can be easily identified. A device (140) for adjusting classification classifies defects into a first class group according to the feature amount of the defects that are obtained from image data obtained from an electron microscope (110), and classifies the defects into a second class group according to the feature amount of the defects classified into the first class group. And, the device (140) for adjusting the classification calculates classification performance by comparing the defects that have been classified into the second class group, and outputs the calculated classification performance in a predetermined display format to an output unit (180).