an image forming apparatus comprises a rotatable photosensitive drum driving mechanism for rotating the photosensitive drum ; and a cleaning blade which is capable of being in contact with the outer circumferential surface of the photosensitive drum and which removes a residual developer on the outer circumferential surface upon contact therewith . a recess is formed at part of the outer circumferential surface and holds lubricant therein ; and the tip end of the cleaning blade feeds the lubricant in the recess to part of the outer circumferential surface of the photosensitive drum which is brought into contact with the cleaning blade to form a thin film of the lubricant upon contacting with the lubricant held in the recess as said photosensitive drum is rotated .