Support carrying an immobilized selective binding substance

A support carrying an immobilized selective binding substance comprising:

• a concavo-convex part containing multiple projections and a flat area surrounding the concavo-convex part, wherein the selective binding substance is immobilized on a surface of top faces of the multiple projections, a difference in height between the top faces of highest and lowest projections of the multiple projections is 50 μM or less, the top faces of the multiple projections are substantially flat, and wherein the flat area is free of concavo-convex structures and higher in height than the top faces of the multiple projections, in which the difference in height between the top faces of the highest projections of the multiple projections and the top face of the flat area is 100 μM or less, the support has a surface with a polymer comprising a structural unit represented by Formula (1), the support surface of the polymer being treated with an alkali or acid, forming carboxyl groups and the selective binding substance is essentially immobilized only on the surface of the top faces of the multiple projections of the concavo-convex portion through the carboxyl groups
• wherein R1, R2 and R3 each represent an alkyl or aryl group or a hydrogen atom.