An electrophotographic image forming apparatus in which a reduction in image density when continuous sheet supply endurance is effected under a low-humidity environment is prevented, and under a high-humidity environment, an image deletion is prevented. A photosensitive member has an undercoat layer, a charge generating layer and a charge transport layer, and the surface layer of the photosensitive member contains a compound of which at least one polymerization functional group has been polymerized or cross-linked and hardened. Also, the hardening of the surface layer is effected by electron irradiation. A temperature raising apparatus for heating the surface of the photosensitive member is controlled by a controlling device to thereby control the surface temperature of the photosensitive member. The controlling device has two or more stages of set temperatures, and uses a high set temperature when the photosensitive member is used under an environment in which the absolute amount of water vapor is great.