To provide a manufacturing method capable of easily manufacturing a periodical nanostructure in which a large number of semiconductor microcrystals of the order of nanometer are formed to range in the thickness direction of a semiconductor substrate and the semiconductor microcrystals are periodically formed in plane of the semiconductor substrate; to provide a field emission electron source capable of improving an electron emission characteristic; and to provide a manufacturing method of the field emission electron source.

The periodical nanostructure is manufactured through: a process of forming a lower electrode 2 on the silicon substrate (semiconductor substrate) 1; a process of forming a plurality of vertical holes 31 periodically arranged on one surface of the silicon substrate 1 according to anodization; and a process of forming silicon microcrystals (semiconductor microcrystals) 33 which range in the thickness direction of the silicon substrate 1 along inner circumferential surfaces of the vertical holes 31 according to anodization. Further, the field emission electron source 10 is manufactured through: a process of forming a silicon oxide film (insulation film) 34 on each surface of respective silicon microcrystals 33 to form a strong field drift part 3; and a process of forming a surface electrode 4 on the strong field drift part 3.