To provide a method for manufacturing a periodic nanostructure, which can easily manufacture the periodic nanostructure having a plurality of nanostructure portions, in which many nanometer-order semiconductor microcrystallines are formed in a row in the thickness direction of a semiconductor material layer, and which are periodically formed in the plane of the semiconductor material layer, in a desired period of the nanostructure portions; and to provide a field emission type electron source capable of improving an electron emission characteristic.

A lower electrode 2 is formed on a single crystal silicon substrate (semiconductor material layer) 1, sites 31 to be arranged periodically on one surface of the silicon substrate 1 are formed, the silicon microcrystallines (semiconductor microcrystallines) 33 in a row in the thickness direction of the silicon substrate 1 are then formed by anodic oxidation, thereby obtaining the periodic nanostructure 10 in which the nanostructure portions 32 are arranged periodically. A silicon oxide film (insulating film) 34 is formed on a surface of each silicon microcrystalline 33, thereby forming a high-field drift portion 3, and a surface electrode 4 is formed on the high-field drift portion 3, thereby providing the field emission type electron source 20.