A process unit includes a rotatable image bearer, an optical writing head to expose the image bearer within an maximum exposure range in an axial direction of the image bearer, a developer bearer, spacers disposed in axial end portions of the image bearer to determine a position of the optical writing head relative to the image bearer and slidingly contact the image bearer, a cleaner disposed downstream from the developer bearer in an image bearer rotation direction, and a remover to slidingly contact the axial end portion of the image bearer to remove a substance adhering thereto. In the axial direction, inner ends of the spacers are positioned inside a toner layer range of the developer bearer extending beyond a largest sheet width. The remover is disposed downstream from the cleaner and crossing a line extending from the inner end of the spacer perpendicularly to the axial direction.