PURPOSE: To obtain a high resolution image of good quality while being able to efficiently detect secondary electrons even when a sample is located extremely adjacent to the object lens by providing not less than two electrodes between the object lens and the sample.

CONSTITUTION: In a secondary electron detection device such as a scanning type microscope having a means of image displaying by radiating the focusint electron rays on a sample while detecting the secondary electrons generated from said sample, plural electrodes 4 for drawing out the secondary electrons are provided between an object lens 1 and the sample 5 for making said electrodes 4 to impress voltage having distribution in the cosine function shape. For instance, the electrodes 4-1W4-8, in which the ring shape is equiangularly divided into eight, are respectively connected with a voltage divider 8, while the voltage having the distribution in the cosine function shape is supplied from a power source 9 for generating a uniform electric field between the object lens 1 and the sample 5 in a relatively wide region. The secondary electrons generated from the sample 5 in the electric field 7 generated by said electrodes are guided up to the region, in which the secondary electron accelerating electric field from the detector 6 oozes out fully, followed by being led into the detector 6 by the acceleration electric field from the detector 6.