An image forming apparatus includes an image bearing member for bearing a toner image; toner image forming means for forming a toner image on the image bearing member; a detecting member for directing light to an object and for detecting the light reflected by the object; a controller for controlling a toner image forming condition of the toner image forming means in accordance with an output of the detecting member with respect to the toner image formed on the image bearing member and an output of the detecting member with respect to the image bearing member; a cleaning member, in contact to the image bearing member, for cleaning the image bearing member; an executing portion for executing, when the output with respect to the image bearing member reaches a reference level, an operation in a cleaning mode in which the cleaning member cleans the image bearing member; and a change portion for changing the reference level in accordance with a use amount of the image bearing member.