To provide a structural body imparted by mechanical strengths such as all the surface scratch resistance and the like by finding out the surface shape required for the structural body having the anti-reflective performance against and transmission improvement performance of light; and to provide a composition capable of forming the structural body having such a specified surface shape.

The structural body has on the surface the convex portions or concave portions which have an average height or depth of 100 nm or more to 1,000 nm or less and which exist in the average cycle of 100 nm or more to 400 nm or less in at least one direction, and is characterized in that this structural body is a polymerized product of a (meth)acrylic-based polymerizable composition by light irradiation, electron-beam irradiation, and/or heating, and in that this (meth)acrylic-based polymerizable composition comprises the (meth)acrylate bifunctional ester having an alkylene glycol chain and having at the both ends of the molecule each one (meth)acrylic group.