An image forming apparatus includes a developer carrying body to transfer developer to a photosensitive body. The developer carrying body has an outer circumference and grooves spaced apart along the outer circumference. The grooves occupy 27% or more of the outer circumference. The developing carrying body is rotatable in a rotational direction that imparts the developing carrying body with a direction of movement that is opposite to a direction of movement of the photosensitive body, at a position between the developer carrying body and the photosensitive body.