An image-forming apparatus for forming image through the electric charging of a photosensitive material drum, exposure to light, developing and transfer, wherein a developing device also works to clean the toner remaining on the photosensitive material; an electric charge for effecting the electric charging has a scorotron charger located within .+-.45.degree. from a perpendicular downwardly drawn from the center of the photosensitive material drum, and has a hole on the side opposite to the opening for charging; and an electric field E.sub.1 between a wire and a grid in the scorotron charger is set to be stronger than an electric field E.sub.2 between the wire and a shield. The invention is further concerned with an image-forming unit used in the image-forming apparatus for forming image wherein said image-forming unit includes a photosensitive material drum having a photosensitive layer of an organic material, a first frame for supporting the photosensitive material drum maintaining the freedom of rotation, a photosensitive material unit having a scorotron charger which is provided on the first frame so as to be positioned within .+-.45.degree. from a perpendicular downwardly drawn from the center of the photosensitive material drum and has a ventilation hole on the side opposite to the opening for charging, a developing device, and a second frame which supports the developing device and also works as a toner container; wherein the first frame and the second frame have a common fulcrum and a resiliently engaging device on the side opposite to the fulcrum, and an electric field E.sub.1 between a wire and a grid in the scorotron charger is set to be stronger than an electric field E.sub.2 between the wire and a shield.