An affinity membrane was prepared from a porous cellulose membrane, and adsorption and recovery of serum proteins were investigated from the viewpoint that affinity membranes are efficacious against separation and purification of biomaterials. Into the cellulose membrane, iminodiacetate (IDA) group that acts as a ligand to metal ions was introduced (Cell-IDA membrane), and then Cu2+ ion was immobilized (Cell-IDA-Cu membrane). Bovine serum albumin (BSA) and gamma-globulin (B gamma G), which are the major proteins in blood, were adopted as model proteins to be separated. The Cell-IDA-Cu membrane had large adsorption capacity for these proteins despite the low degree of modification. The amounts of proteins adsorbed on the Cell-IDA-Cu membrane increased with increasing pH, and B gamma G was adsorbed more than BSA. High protein recoveries from the Cell-IDA-Cu membrane were obtained. The separation of these proteins was also conducted under the optimum conditions of adsorption and recovery, and B gamma G was concentrated more than BSA although the initial concentration of B gamma G was lower than that of BSA.