A developing apparatus is used in an electrophotographic image forming apparatus. Developing units form corresponding developer images. A frame holds the developing units therein in position so that the developing units are movable independently by a distance relative to the frame. An urging member is disposed across the frame and each developing unit and urges each developing unit against the frame. An elastic sealing member secured to the frame and in intimate contact with each of the developing units when the corresponding developing unit is attached to the frame. The sealing member seals a gap between the frame and each of the developing unit.