An image forming apparatus includes a photosensitive member and a charging roller to which a direct current voltage is applied. A difference between a first potential (before charging) and a second potential (after charging) of a surface of the photosensitive member in an image forming operation is smaller than 100 V. The charging roller includes a shaft portion, an elastic layer provided on an outer periphery of the shaft portion, and a surface layer provided on an outer periphery of the elastic layer. A ten point height of roughness profile Rz (μm) and a root mean square slope RΔq with respected to a surface of the charging roller satisfy Rz≥7 and RΔq≤0.1.