Patent ID: 9679738
Date: 2017-06-13
CPC Classifications: G01N,H01J

Claim:
1. An electron microscope having a light source of an electron beam, an irradiating optical system configured by a plurality of electron lenses for irradiating a sample with the electron beam emitted from the light source, a movable irradiation aperture belonging to the irradiating optical system for changing an irradiating amount of the electron beam to the sample, a sample holding device for holding the sample which the electron beam irradiates, an imaging lens system configured by the plurality of electron lenses for focusing an image of the sample or a diffraction pattern of the sample, an observing face for observing the image of the sample or the diffraction pattern of the sample by the imaging lens system, and a recording device for recording the image of the sample or the diffraction pattern of the sample, the electron microscope comprising: a movable first aperture for selectively transmitting a portion of the electron beam transmitting the sample between a first imaging lens disposed at an uppermost stream side in a progressing direction of the electron beam in the electron lens belonging to the imaging lens system and the sample holding device; and a deflecting device for deflecting the electron beam to a downstream side in the progressing direction of the electron beam of the first imaging lens, an axis deviation of the electron beam generated in accordance with a change in a focal length of the first imaging lens is corrected by the deflecting device, and the image of the sample and the diffraction pattern of the sample are observed by changing the focal length of the first imaging lens.