An electrophotographic photosensitive body includes a substrate and a photosensitive layer. In the electrophotographic photosensitive body, a reflectance to an exposure light L1 is defined as a first reflectance, and a reflectance of an eliminating light is defined as a second reflectance. The first reflectance is positively correlated with a light intensity rate of the exposure light L1, and the second reflectance is positively correlated with the light intensity rate of the exposure light L1 in a first case, while is negatively correlated with the light intensity rate of the exposure light L1 in a second case. In the first case, an amount of change of the first reflectance to an amount of change of the light intensity rate of the exposure light L1 is less than 1. In the second case, an amount of change of the first reflectance to an amount of change of the light intensity rate of the exposure light L1 is more than 1.