A developing device that attaches/detaches to/from a main body of an image forming apparatus includes a first frame that supports a photosensitive member, a second frame that supports a developing roller, and a connecting bracket in which a fixed supporter couples to a side portion of the first frame, a flexible supporter that couples to a side portion of the second frame, and an elastic arm connecting the fixed supporter and the flexible supporter to each other to provide an elastic force that may elastically bias the developing roller toward the photosensitive member, are integrally formed.