SCANNING ELECTRON MICROSCOPE

PROBLEM TO BE SOLVED: To suppress a loss of information of a secondary electron to the minimum so as to achieve observation of the information of the secondary of electron having a high S/N ratio by disposing on a shaft of a plurality of beam deflectors of a magnetic field type, shifting the axis of a primary electron beam by a predetermined distance, and detecting a secondary electron emitted from a sample by means of secondary electron detectors. SOLUTION: Upper and lower beam deflectors 17, 18 disposed on a shaft are deflected, at two stages, a primary electron beam 5 generated by an electron gun 4, to shift the axis of the electron gun 4 and the axis of an objective lens 2 by a predetermined distance in a horizontal direction. An image is focused by the objective lens 2, and then, the finely throttled primary beam 5 is irradiated on a sample 1. After surface scanning, a secondary electron 16 emitted from the sample 1 is detected by a secondary electron detector 9 disposed above the objective lens 2. The secondary electron 16 deflected in a reverse direction by the lower beam deflector 18 is detected by another secondary electron detector 10. Consequently, it is possible to suppress a loss of information of the secondary electron to the minimum, thus achieving observation of a clear secondary electron image.