An image forming apparatus having excellent cleaning property for an
electrophotographic photoreceptor and capable of forming a high-quality,
high-resolution image. A surface free energy (.gamma.) of a photoreceptor
(2), which is provided in the image forming apparatus (1), is set to 20
to 35 mN/m. A volume average diameter of toner particles included in a
developer stored in a developing unit (29) to develop an electrostatic
latent image and form a toner image is set to 4-7 .mu.m When .gamma. of
the photoreceptor (2) is set to within a small range as the particle size
of toner is reduced, even small-particle-size toner having increased
specific surface area and largely affected by a inter-molecular force is
limited in adhesion to the surface of the photoreceptor (2) to provide a
good cleaning property and a high-quality image can be formed.