In a conventional micro-channel plate (MCP), a secondary electron (SE) detector or a semi-conductor detector the number of the electrons is amplified through its own structure. For such amplification a small voltage difference is applied externally or generated due to its own structure and material. The electric current of electrons undergoing the above-described procedure is amplified by an external amplification circuit. In the present invention electrons—resulting from the collision of the electron beam generated by a microcolumn—are detected by surrounding conductive wiring. The detected electrons are amplified using an amplification circuit on the outside similar to a conventional detection method.