The present invention relates to an electrophotographic apparatus in which maximum potential difference ΔVD (volt) in a potential of a dark portion of the electrostatic image in the longitudinal direction, maximum potential difference ΔVL in a potential of a light portion of the electrostatic image in the longitudinal direction, a value a (1/volt) represented by (variation amount in density, in the longitudinal direction, in the image formed by developing the light portion with the developing means)/(the maximum potential difference ΔVD) and a value b (1/volt) represented by (variation amount in density, in the longitudinal direction, in the image formed by developing the light portion with the developing means)/(the maximum potential difference ΔVL) satisfy a relation: 0.3 ≤ a × ΔVD + b × ΔVL ≤ 0.3 in which 100 ≥ |ΔVD| ≥ 20 and 100 ≥ |ΔVL| ≥ 20.