| 摘要 |
PROBLEM TO BE SOLVED: To provide a charged particle ray device that has a charged-particle optical system capable of forming an image by zooming out charged particle rays and is not affected by stray light when observed at a high magnification. SOLUTION: Between the pupil 25 and MCP 8, a diaphragm 23 determined by an open angle at the high magnification is fitted so as to cut stray light 22 of electron rays which do not contribute to image formation. That is to say, the aperture of the diaphragm 23 is made to be an aperture through which only the electron rays directly reaching the image-formation face of MCP 8 can pass at the highest magnification. Thus, only electron rays 21 which contribute to image formation are emitted to MCP 8, other electron rays 22 which do not contribute to image formation are cut, so that these electron rays do not reach the detection face of MCP 8 by being reflected by a mirror cylinder 19, and an excellent observation image can be obtained.
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