An object of the invention is to provide an image forming apparatus being excellent in cleaning property for an electrophotographic photoreceptor and capable of forming a high-quality, high-resolution image. A surface free energy (γ) of a photoreceptor (2) which is provided in the image forming apparatus (1) and is exposed to a light corresponding to image information for formation of an electrostatic latent image is set to 20 to 35 mN/m. A volume average diameter of a 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 mum. When γ of the photoreceptor (2) is set to within a small range as the particle size of toner is reduced, even small-particle-size toner hence increased in specific surface area and largely affected by a inter-molecular force is limited in adhesion force to the surface of the photoreceptor (2) to provide a good cleaning property, whereby a cleaning property is enhanced and at the same time a high-quality image can be formed.