To provide a developing device, a process cartridge, and an image forming apparatus which maintain image quality by previously recognizing the relation among toner deterioration, the number of times of imaging, and abrasion wear and preventing a doctor roller from partially being worn away by varying doctor roller driving intervals when the abrasion wear varies, and further to provide a developing device, a process cartridge, and an image forming apparatus that maintain image quality by preventing a doctor roller from partially being worn away by suppressing extension of a wait time as much as possible.

Disclosed are a developing device 200, a process cartridge 1c, and an image forming apparatus which change reversing rotation operation timing of a developing roller 210 by counting used sheets.