A developing device for developing an electrostatic latent image formed on an electrophotographic photoreceptor includes a hollow developing roller, a support member inserted in the hollow developing roller to support the developing roller, a flange member having a first engaging portion engaging with an outer surface of the support member and a second engaging portion engaging with an inner surface of the developing roller, and a gap-holding member disposed at one end of the developing roller, the gap-holding member having an abutment abutting against the electrophotographic photoreceptor for maintaining a gap between the developing roller and the electrophotographic photoreceptor. The abutment overlaps with the second engaging portion in the longitudinal direction of the developing roller.