Image forming apparatus

In an image forming apparatus, in the case where a time necessary for a developer bearing member to rotate from a measurement position where an attracting unit attracts the toner on the developer bearing member to a developing position at which an electrostatic latent image on the photosensitive member is developed by a toner on the developer bearing member is represented by a time Tqcm, a time necessary for the photosensitive member to rotate from an exposure position at which an exposure unit exposes the photosensitive member to the developing position is represented by a time Tetd, and a time necessary for a control unit to control an exposing condition based on a charge amount measured by a measuring unit is represented by a time Tp, the attracting unit is disposed so that Tqcm Tedt+Tp holds true.