A crystal material lattice strain evaluation method includes illuminating a sample having a crystal structure with an electron beam in a zone axis direction, and selectively detecting a certain diffracted wave diffracted in a certain direction among a plurality of diffracted waves diffracted by the sample. The method further includes repeating the illuminating step and the selectively detecting step while scanning the sample, and obtaining a strain distribution image in a direction corresponding to the certain diffracted wave from diffraction intensity at each point of the sample.