Corrugated pattern forming sheet and method for manufacturing the same, and method for manufacturing antireflector, retardation plate, original process sheet plate, and optical element

A corrugated pattern forming sheet exhibiting excellent performance when being used as optical elements, such as an antireflector and a retardation plate is provided. A corrugated pattern forming sheet of the invention includes a resin layer, and a hard layer provided at least in a portion of an outer surface of the resin layer. The hard layer is made of a metal or a metallic compound. The hard layer has a wavelike corrugated pattern. The average pitch of the corrugated pattern is 1 μm or less, and the average depth of the bottom of the corrugated pattern is 10% or more given an average pitch of 100%.