To quicken the defect analysis of a semiconductor memory by automatically updating a defect mode criterion when the number of defects of the FMB data of the semiconductor memory is equal to or more than a threshold value.

This semiconductor defect analyzing device is provided with a measured data memory device 3 for obtaining and storing the FBM data of a semiconductor memory, and a CPU 1 having a creating means for creating the defect mode criterion of the semiconductor memory, a calculating means for classifying defect modes to calculate the characteristics of the defect modes based on the FBM data stored in the measured data memory device 3, and an updating means for updating the defect mode criterion when the amount of characteristics is compared with the defect mode to find that its ratio is equal to or more than the threshold value of the defect mode criterion.