IMAGE FORMING APPARATUS

An image forming apparatus includes an image bearing member, a developing unit to which a supply container is detachably mountable, a first developer amount acquiring portion, a second developer amount acquiring portion, a first notifying portion, a storing portion, a setting portion, a second notifying portion, and a controller. This controller carries out control so as to be capable of executing an operation in an operation mode in which a developer image is capable of being formed by the developing unit, until the supply container connected to the developing unit is exchanged after first notification is provided by the first notifying portion. The setting portion sets the usable amount depending on the exchange number information.