PURPOSE: To realize an energy filter image by use of a simple means by providing a deflecting means out of the axis of an intermediate lens having a large non-axial color aberration so that electron rays pass the deflection means after passing through a limiting diaphragm, and inserting an energy selecting diaphragm into the surface upon which the diffracted image of the intermediate lens is formed.

CONSTITUTION: Electron rays 2, after being transmitted by a film sample 1, are imaged as an electron-ray image 8 upon a fluorescent plate 7 by means an objective lens 3, an intermediate lens 4, and a first and a second projection lenses 5 and 6. Here, when a limiting visual-field diaphragm is inserted on the optical axis, into the position of the image surface of the lens 3, since the shadow of the diaphragm appears around the central part of a linear image formed upon the plate 7, the sample 1 is moved within a surface which is vertical to the optical axis so that an image 8a of the observed sample area is obtained in the center of the plate 7. In addition, an energy selecting diaphragm 16 is inserted into a surface 15 upon which an image diffracted by the lens 4 is formed, and the positional adjustment of the diaphragm 16 is performed so that only a specific peak among the energy spectrum displayed on the plate 7 is displayed.