US Patent 7787184 Member having antireflection structure

A reflection of unnecessary light, which should be prevented, can be suppressed, and occurrence of stray light can be reduced using a member having an antireflection structure, comprising a plate-like portion 2, and an aperture portion 3 formed in the plate-like portion 2, wherein the antireflection structure having an aspect ratio of 1 or more and comprising structural elements arranged in an array form at a period smaller than the shortest wavelength of light, the reflection of which should be prevented, is formed on an inner wall 4 of the aperture portion 3.