Image forming apparatus

An image forming apparatus comprising:

• a cartridge detachably mountable to a main assembly of the image forming apparatus, said cartridge including a developer accommodating portion for accommodating a developer, and an operation member;
• a remaining amount detector for detecting a remaining amount of the developer in said developer accommodating portion when an image forming operation is not carried out while said operation member is in operation;
• an operation amount detector for detecting a cumulative operation amount of said operation member,
• wherein an end of a service life of said cartridge is discriminated when said remaining amount detector detects that the remaining amount of the developer becomes less than a predetermined amount, and the end of the service life of said cartridge is discriminated when said operation amount detector detects an end of a service life of said operation member;
• and
• a setting device for setting, on the basis of a remaining amount of the developer detected by said remaining amount detector and the cumulative operation amount of said operation member detected by said operation amount detector, timing of subsequent remaining amount detection of said remaining amount detector.