To prepare a large amount of an antigen-specific immunosuppressive cell holding an intact strong antigen-specific immunosuppressive ability by culturing a human cell in the presence of an antigen and further culturing the resultant cultured human cell in a culture tool containing an immobilized protein.

A human cell is cultured in the presence of one or more antigens and the resultant cultured human cell is further cultured in a culture tool containing an immobilized protein which is an antibody or the like against the surface antigen of the human cell. The obtained cell is useful for treating diseases associated with anomalous acceleration of the immunological system such as treatment of autoimmune diseases or suppression of rejection of organ transplantation with slight adverse effects.