TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The substrate material is silicon, silicon nitride, glass, metal, heat resistant resin or metal oxide. Preferred Element: The functional element filled in pore of porous nanostructure is optoelectronic device, semiconductor element or magnetic element.    TECHNOLOGY FOCUS - POLYMERS - Preferred Copolymer: The phase separation structure of block copolymer is sea-island structure in which one side is phase separated into island-like region and other side is phase separated into sea region. The volume ratio of polymer components comprised in the block copolymer is 1:99-15:85 or 85:15-99:1, preferably 20:80-35:65 or 65:35-80:20. The phase separation structure of block copolymer is cylinder structure in which one side is phase separated into cylinder shaped region. The length direction of cylinder structure is perpendicularly or parallely arranged with respect to substrate surface. The island like region or cylinder shaped region in phase separation structure of the block copolymer is formed two-dimensionally as monolayer on the substrate.Preferred Components: The polymer components are polymer component having carbon double bond in its principal chain and polymer component which does not have carbon double bond in its principal chain. The polymer component having carbon double bond is polyisoprene, polybutylene and/or polychloroprene. The polymer component not having carbon double bond is polystyrene, polyethylene, polypropylene, polyvinyl chloride, polymethylmethacrylate, polyacrylamide and/or polyacrylonitrile.Preferred Properties: The width of substructure portion is less than magnitude of grain of the block copolymer. The diameter of island-like region in phase separation structure of block copolymer is 100 nm or less, and sequential interval of the island-like region is 10-100 nm. The diameter and length of cylinder shaped region in phase separation structure is 100 nm or less and 50 nm-50 mm, respectively. The sequential interval of the cylinder shaped region is 10-100 nm. The aspect ratio (ratio of width/height) of substructure portion is 0.1-10. The substructure portion has height of 1 microns or less, width of 100 nm-10 microns and interval of 25-500 nm.