| 摘要 |
PROBLEM TO BE SOLVED: To analyze with high accuracy in a minute region by increasing an acceleration voltage for controlling deviation against radiation optical system as much as possible. SOLUTION: An arithmetic and logic unit 18 for relative correction controls a power supply 15 for a radiation lens control based on a control signal from a superimposed voltage control means 14 for controlling the current from the radiation lens control power supply 15 to the radiation lens 3. When a loss image of energy lossΔE is observed in a condition set to observe an image with an acceleration voltage V which imparts the energy of E to an electron e by using an energy filter provided with focus adjustment for an electron e with energy E, the acceleration voltage is set to V+ΔV for increasing energy of the electron up to E+ΔE, and the irradiation lens is supplied with a current based on the acceleration voltage V+ΔV.
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