An image forming device includes: first and second photosensitive drums; first and second drum cleaners for removing waste developer on the first and second photosensitive drums respectively; first developer cartridge having a first waste developer chamber; a second developer cartridge having a second waste developer chamber; a belt in contact with the first and second photosensitive drums; a belt cleaner for removing waste developer on the belt; a belt waste developer conveyer for conveying the waste developer removed by the belt cleaner; a first conveyer for conveying the waste developer removed by the first drum cleaner; a second conveyer for conveying the waste developer removed by the second drum cleaner to the second waste developer chamber; and a third conveyer for conveying the waste developer conveyed by the first conveyer and the waste developer conveyed by the belt waste developer conveyer to the first waste developer chamber.