To improve the efficiency and throughput, the biointeraction between an antigen and antibody was used for refolding in a packed column, in which an antibody against carbonic anhydrase coupled on a gel support was used as a template ligand. A denatured solution of CAB was mixed with a refolding buffer in a mixing chamber, and was supplied to the antibody-coupled column for refolding. Higher refolding efficiencies were obtained in the column than by the batch dilution method at relatively low concentrations of denaturant. By increasing the adsorption capacity of the column, the efficiency of refolding, as well as the throughput, could be increased.