It is intended to provide a method for immobilizing, onto a column carrier, a compound having a sulfo group or a compound to which a sulfo group can be added. The method comprises immobilizing the compound onto the column carrier using a linker comprising: a sulfo group-binding group capable of forming a bond with the sulfo group in the compound; and a carrier-binding group capable of forming a bond with a group present on the surface of the column carrier.