The benefit of a material having a microscopic pattern with a period not larger than a wavelength of visible light on the surface has been recognized recently due to its functionalities, such as an antireflection function or a lotus effect. Especially, a steric structure called as a moth-eye structure is known as an effective antireflection means due to gradual increase from a refractive index of air to a refractive index of a material.
As a process for forming a microstructure on a material surface, direct fabrication of the material is possible, however generally a process of producing a mold with a negative microstructure and transcribing the same onto the material is superior in terms of productivity and economy. As the process for forming a microscopic pattern, an electron beam lithography and laser interference lithography have been long known, and anodic oxidized porous alumina has recently drawn attention, with which a mold can be produced more easily (e.g. Patent Document 1).
For imparting the microstructure shape to the material surface as described above, a large area mold with high economical efficiency, or a mold enabling continuous production with high productivity and economy is often used.
A process including forming a microscopic pattern by lithography, replicating the same to produce metallic stampers, assembling a plurality of the same to cover a large area and attaching the same onto a roll (e.g. Patent Document 2), or a process including forming a microscopic pattern by lithography on an inner surface of a hollow cylindrical original mold, forming a metal layer by electroforming, removing the original mold and inserting a support roll for supporting (e.g. Patent Document 3) have been proposed.    Patent Document 1: Japanese Patent Laid-Open No. 2005-156695    Patent Document 2: Japanese Patent Laid-Open No. 2001-264520    Patent Document 3: Japanese Patent Laid-Open No. 2005-35119
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