PURPOSE: To speed up the scanning, by poroviding the deflection system correcting the spherical aberration of the electron lens, in the electron microscope performing angle scanning.

CONSTITUTION: Two stage of deflection systems D1 and D2 are placed at the incident electron ray of the electron lens (objective lens)2 of the electron microscope performing angle scanning. When the electron rays are radiated with an incident angle α to the test piece 1, the electron rays intersect the light axis 3 close to Csα2 with the spherical aberration of the lens 2, where Cs is the coefficient of spherical aberration. Accordingly, when the electron rays are incident to the lens 2 from the point O2 apart from the lens 2 by the distance Δb=Csα2 by means of the deflection system D2, the rays intersect the light axis 3 on the test piece 3 and the position of radiation can be fixed to one point. Further, the deflection components aX and aY of X and Y direction orthogonal to the light axis 3 and the deflection angles θ1X, θ1Y, θ2X and θ2Y are satisfied with a given relation and the deflection systems D1 and D2 are deflected with the circuit generating the signal given the function of aX and aY. Thus, the scanning of high speed can be made without being affected with the spherical aberration.