An image forming device includes a permitting unit and a moving unit. The permitting unit selectively establishes a first positional relationship in which photosensitive members contact an endless belt and a second positional relationship in which the photosensitive members separate from the endless belt. The moving unit moves a charger between a first position confronting the corresponding photosensitive member at a rear side thereof in a juxtaposed direction and a second position moved away from the first position. The endless belt confronts the photosensitive members at a top side thereof in an orthogonal direction. Each developer cartridge confronts the corresponding photosensitive member at a bottom side thereof. The developer cartridge is attachable to and detachable from a main casing while moved past a front side of the corresponding photosensitive member when the second positional relationship is established and the neighboring charger is in the second position.