The present invention provides an electron beam measurement technique for measuring the shapes or sizes of portions of patterns on a sample, or detecting a defect or the like. An electron beam measurement apparatus has a unit for irradiating the patterns delineated on a substrate by a multi-exposure method, and classifying the patterns in an acquired image into multiple groups according to an exposure history record. The exposure history record is obtained based on brightness of the patterns and a difference between white bands of the patterns.