The purpose of the present disclosure is to provide an adsorbing material in which the physical strength of a carrier material is maintained and immunosuppressive proteins are efficiently adsorbed. The present disclosure provides an immunosuppressive-protein-adsorbing material that includes a water-insoluble carrier to which is bonded one or more nitrogen-containing compounds selected from polyamines represented by a prescribed formula and aliphatic amines represented by a prescribed formula, the total amount of amino groups on the water-insoluble carrier being greater than 0 µmol and no greater than 2500 µmol per gram, and the amount of primary amino groups on the water-insoluble carrier being no greater than 450 µmol per gram.
