An image forming apparatus has the following characteristics: the diameter of an exposure beam for exposing a latent image is not more than twice a minimum dot recording period p in peak intensity 1/e2, and the value of a spatial frequency characteristic function of a latent image defined by the thickness of a photoreceptor layer, the dielectric constant of the photoreceptor layer, the thickness of a developer layer, the dielectric constant of the developer layer and a spatial frequency &ohgr; defined as &ohgr;=&pgr;/p is at least 0.3. The image forming apparatus having such characteristics can reproduce an image of high resolution exceeding 600 to 1200 DPI with high fidelity.