Patent ID: 7425702

Claim:
A charged particle beam apparatus having an electron gun, two or more lens stages for finely focusing and irradiating a primary charged particle beam emitted from said electron gun on a specimen, deflectors for two-dimensionally scanning said primary charged particle beam on said specimen, signal detectors for detecting a signal generated from said specimen by irradiation of said primary charged particle beam, and image display means for displaying, as images, signals of said signal detectors, said apparatus comprising: voltage controllers for controlling a voltage applied across a cathode of said electron gun and an extraction electrode for the primary charged particle beam and a voltage applied across said cathode and an accelerating electrode for accelerating said primary charged particle beam; a condenser lens excitation control unit for controlling the lens excitation of said condenser lens; means for detecting a difference between a control target value of a crossover position of said primary charged particle beam passing through said condenser lens and an actually measured position; and means for taking the control target position of crossover for said condenser lens as a blanking deflection start point to serve as crossover position detection means so as to control a blanking voltage applied to a deflecting electrode device for blanking and detecting a movement of an image at the time that the blanking deflection starts.