Patent ID: 8304722

Claim:
A charged particle beam apparatus for obtaining an image of a specimen by scanning a charged particle beam on the specimen with a scanner, and a lens system for focusing the charged particle beam, comprising: a charged particle beam source for generating the charged particle beam; a specimen stage for mounting and moving the specimen; a beam deflector for deflecting said charged particle beam; a detector for detecting electrons caused by an interaction of the charged particle beam and the specimen; an arithmetic processing part for performing an image operation; and a display part for displaying the image of the specimen, wherein: said arithmetic processing part obtains a first displacement of a part on a first image captured in a first magnification and a second displacement of a part on a second image captured in a second magnification, each displacement is obtained by giving a same amount of deflection to the beam deflector, wherein the amount of displacement is based on a measured pitch distance at each magnification, and said arithmetic processing part determines a magnification error based on a difference between the first displacement and the second displacement converted by using a value of the first magnification and a value of the second magnification, and calculates a calibrated magnification using the magnification error.