Patent ID: 7612336

Claim:
A scanning electron microscope comprising: an electron source; an objective lens for focusing an electron beam emitted from the electron source on a sample; a monochromator that is disposed between the electron source and the objective lens and that monochromatizes energy of the electron beam, a first scanning deflector that is disposed between the monochromator and the sample, a first focusing lens for adjusting focusing of the electron beam entering the monochromator; a first astigmatism correcting lens for correcting astigmatism of the electron beam entering the monochromator, a second scanning deflector for scanning the electron beam on an electron-beam adjustment sample disposed where the electron beam is focused in the monochromator, wherein the first focusing lens, the first astigmatism correcting lens and the second scanning deflector are between the electron source and the monochromator; and a controller for controlling the first focusing lens and the first astigmatism correcting lens based on an image that is obtained by the second scanning deflector's scanning.