Electron beam apparatus having electron analyzer and method of controlling lenses

A method of controlling lenses in an electron beam apparatus having an illumination optical system consisting of lenses and deflection means for illuminating electrons at a specimen, the electrons being produced and accelerated from an electron gun, an imaging optical system for imaging electrons transmitted through the specimen positioned within a magnetic field of an objective lens, and the electron analyzer having a detection system for detecting the imaged electrons and energy selection means for energy-dispersing the detected electrons and selecting electrons having a certain energy, said method comprising the steps of:

• varying an accelerating voltage of the electron gun to shift the detected energy of electrons;
• and
• correcting signals supplied to the lenses and deflection means of the illumination optical system using amounts of correction for focus and position each obtained by multiplying an energy shift value corresponding to a variation in the accelerating voltage by a corrective coefficient.