An image forming apparatus includes a charging roller for charging a surface of a photoconductive layer in a photoreceptor so as to have a prescribed polarity, a first exposing unit which is arranged on a downstream side of the charging roller on the basis of a direction in which the photoreceptor moves, a developer unit which is placed on a downstream side of the first exposing unit and which keeps toner, to which a charge with a polarity opposite to the prescribed polarity is applied, in contact with a photoconductive layer, and a second exposing unit for directing light generated according to an image signal to a back of the photoconductive layer at a contact position of the toner and the photoconductive layer. The first exposing unit directing light reflected from a document to which a light is applied to the surface of photoconductive layer so as to form a first electrostatic latent image. The second exposing unit forms a second electrostatic latent image by interlocking or synchronizing with the developing operation of the developer unit. This makes it possible to easily form a synthetic image at a high speed by superimposing characters printed by a printer function onto a copy image formed by a copying function, for example.