Patent ID: 8641884

Claim:
A method of fabricating a mold that has an inverted motheye structure in its surface, the inverted motheye structure having a plurality of recessed portions whose two-dimensional size viewed in a direction normal to the surface is not less than 10 nm and less than 500 nm, the method comprising the steps of: (a) anodizing a surface of an aluminum film or aluminum base via an electrode that is in contact with the surface, thereby forming a porous alumina layer which has a plurality of very small recessed portions; (b) after step (a), allowing the porous alumina layer to be in contact with an etchant, thereby enlarging the plurality of very small recessed portions of the porous alumina layer; and (c) after step (b), further anodizing the surface via the electrode to grow the plurality of very small recessed portions, wherein the aluminum film or aluminum base is made of aluminum with a purity of 99.99 mass % or higher, the electrode includes a first electrode portion which is made of aluminum with a purity of 99.50 mass % or lower and a second electrode portion which is made of aluminum with a higher purity than the aluminum of the first electrode portion and which is interposed between the surface and the first electrode portion, and step (a) and step (c) are performed with the second electrode portion being in contact with the surface in an electrolytic solution.