An image forming device includes: a main casing; a holder unit; a plurality of image bearing members; a plurality of developing units; a plurality of toner boxes; a first acting portion; a second acting portion; and an abutment member. The holder unit is configured to be movable in a moving direction between an accommodated position and a pull-out position. The plurality of image bearing members are held by the holder unit and are juxtaposedly arrayed in the moving direction with intervals between neighboring image bearing members. The plurality of developing units are held by the holder unit in one to one correspondence with the plurality of image bearing members. The plurality of toner boxes are detachably attachable to the holder unit in one to one correspondence with the plurality of developing units. Each toner box is detachably attachable to the holder unit at the pull-out position.