Image forming apparatus

An image forming apparatus includes a driving device, a transfer body, a toner detector, an error notification device, and a controller. The toner detector detects, at a preparation running and while the driving device drives a latent image bearer, one of a toner adhesion amount at a background portion of the latent image bearer and a toner adhesion amount at a background corresponding region of a transfer body. The error notification device notifies a user of an error with the toner adhesion being equal to or greater than a predetermined threshold value. The driving device stops only a developer bearer after driving both the latent image bearer and the developer bearer at the preparation running, but before a trailing edge of a detection target region of one of the background portion of the latent image bearer and the background corresponding region advances to an opposite position to the toner detector.