| 摘要 |
PURPOSE:To observe an organization structure of living thing sample at a high contrast without a false structure by suitably setting a spheical aberration coefficient of an image forming lens system, a chromatic aberration coefficient, and a relative compensation value of the acceleration voltage. CONSTITUTION:Coefficients Cs and Cc of an image forming system of a transmission type electron microsope are set to satisfy equations (I) and (II) respectively, where Csmm. is a spherical aberration coefficient, Ccmm. is a chromatic aberration coefficient, and U volt is a relative cmpensation value. Furthermore, the maximum multiplying coefficient of the image forming lens system is made 5,000 times or more. Accordingly, the spherical aberration coefficient can be set so as to have a constant relation to the accelerating voltage of the electron microscope, and the chromatic aberration coefficnient can be also set so as to have a contant relation to the product of the accelerating voltage and the spherical aberration coefficient, thus the observation image with a high contrast and of a good quality can be obtained. |
