An electron beam emitted from a field-emission electron source array passes through a plurality of through holes formed in a mesh structure and reaches a target. Each of the plurality of through holes in the mesh structure has an opening on a side of the field-emission electron source array and an electron beam passageway that continues from the opening. The mesh structure is formed of a silicon-containing material doped with a N-type or P-type material. In this way, it is possible to suppress a decrease in the amount of the electron beam reaching the target while securing a mechanical strength of an electrode provided with a large number of through holes, and suppress expansion of the electron beam on the target.