An image forming apparatus including: an image bearing member having a photoconductive layer of a capacitance per unit area of 1.7.times.10.sup.-6 (F/m.sup.2) or more; and a developing device having a developer carrying member to which development voltage is applied for developing a latent image to form a toner image on the image bearing member, wherein the following expression is satisfied:.gtoreq..times..times..times..times..times. ##EQU00001## where Q/M (C/g): an electric charge quantity per unit weight of the toner image, Vcont: a potential difference between a surface potential of the image bearing member and a direct current component of the development voltage, M/S (g/m.sup.2): a toner weight per unit area of the maximum density portion, L.sub.t (m): a toner layer thickness in the maximum density portion, L.sub.d (m): a photoconductive layer thickness, .epsilon..sub.t: a relative permittivity of the toner layer, .epsilon..sub.d: a relative permittivity of the photoconductive layer, and .epsilon..sub.0 (F/m): a vacuum permittivity.