Patent ID: 9466457
Filing Date: 2016-10-11
CPC Classification: H01J

Claim Text:
1. An observation apparatus comprising: a charged particle optical tube that irradiates a sample with a primary charged particle beam; a vacuum pump that evacuates the inside of the charged particle optical tube; a diaphragm arranged to remain out of contact with the sample and to separate a space in which the sample is placed from the charged particle optical tube, the diaphragm being detachable and allowing the primary charged particle beam to permeate or pass therethrough; an optical microscope positioned on the opposite side of the charged particle optical tube across the diaphragm and the sample, the optical microscope having an optical axis thereof aligned with at least part of an extension of the optical axis of the charged particle optical tube; and an optical axis adjustment mechanism configured to adjust and fix a position of the optical axis of the optical microscope so that the center of the diaphragm is positioned on the optical axis of the optical microscope.