An image forming apparatus 100 includes detection means 116 which detects an image characteristic of an image formed on an image bearing member 103; a first control means which controls a toner concentration in the developer, based on a detection result by the detection means, of an image characteristic of a first reference image for a first control for controlling the toner concentration in the developer; second control means which controls an image parameter, different from the toner concentration in the developer, thereby controlling an image density, based on a detection result by the detection means, of an image characteristic of a second reference image for a second control, different from the reference image for the first control; and correction means 231 which receives detection results of both image characteristics of the first and second reference images, and which, based on the detection result of the image characteristic of either of the reference images for the first and second controls, corrects the other control.