A developer container to be removably installed in an apparatus body of an image forming apparatus, the developer container comprising: a container body to contain developer; a shutter to open and close an opening (34a1) of the developer container in conjunction with installation and removal of the developer container to and from the apparatus body, the opening (34a1) into which a nozzle of the apparatus body is inserted; a guide rod formed together with the shutter in one piece, the guide rod extending in an opening and closing direction of the shutter inside the developer container; a holder including: a holding portion disposed opposite the shutter in the developer container; a fitting portion having the opening (34a1), to fit the container body; and a bridge portion to connect the holding portion and the fitting portion inside the developer container; and a compression spring wound around the guide rod, facing the bridge portion between the shutter and the holding portion, to urge the shutter in a direction to close the opening (34a1), wherein the shutter is pushed by the nozzle against an urging force of the compression spring in conjunction with the installation of the developer container to the apparatus body and moves into the developer container together with the guide rod, to open the opening (34a1), wherein the shutter is released by the nozzle in conjunction with the removal of the developer container from the apparatus body and moves toward the opening (34a1) together with the guide rod by the urging force of the compression spring, to close the opening (34a1), and wherein a circumferential area around the guide rod and the compression spring that faces the bridge portion is smaller than a circumferential area around the guide rod and the compression spring that does not face the bridge portion, characterized in that the holding portion includes at least two portions to support the guide rod movably in the opening and closing direction, wherein the holding portion includes a U-shaped or hollow-squared frame having two holes (34c1, 34c2) separated from each other in the opening and closing direction, wherein the guide rod is configured to fit into the two holes (34c1, 34c2). a container body to contain developer; a shutter to open and close an opening (34a1) of the developer container in conjunction with installation and removal of the developer container to and from the apparatus body, the opening (34a1) into which a nozzle of the apparatus body is inserted; a guide rod formed together with the shutter in one piece, the guide rod extending in an opening and closing direction of the shutter inside the developer container; a holder including: a holding portion disposed opposite the shutter in the developer container; a fitting portion having the opening (34a1), to fit the container body; and a bridge portion to connect the holding portion and the fitting portion inside the developer container; and a holding portion disposed opposite the shutter in the developer container; a fitting portion having the opening (34a1), to fit the container body; and a bridge portion to connect the holding portion and the fitting portion inside the developer container; and a compression spring wound around the guide rod, facing the bridge portion between the shutter and the holding portion, to urge the shutter in a direction to close the opening (34a1), wherein the shutter is pushed by the nozzle against an urging force of the compression spring in conjunction with the installation of the developer container to the apparatus body and moves into the developer container together with the guide rod, to open the opening (34a1), wherein the shutter is released by the nozzle in conjunction with the removal of the developer container from the apparatus body and moves toward the opening (34a1) together with the guide rod by the urging force of the compression spring, to close the opening (34a1), and wherein a circumferential area around the guide rod and the compression spring that faces the bridge portion is smaller than a circumferential area around the guide rod and the compression spring that does not face the bridge portion, characterized in that the holding portion includes at least two portions to support the guide rod movably in the opening and closing direction, wherein the holding portion includes a U-shaped or hollow-squared frame having two holes (34c1, 34c2) separated from each other in the opening and closing direction, wherein the guide rod is configured to fit into the two holes (34c1, 34c2).