An electrophotographic photoreceptor high in sensitivity and contrast potential after light irradiation is disclosed. The photoreceptor comprises an electroconductive substrate having thereon a photoconductive layer comprising a charge generating layer comprising a charge generating material, and a charge transporting layer comprising a charge transporting material, wherein the ionization potential IPg of the charge generating material is lower than the ionization potential IPt of the charge transporting material, the difference therebetween is 0.35 eV or less, and the difference between the ionization potential IPg1 of the charge generating layer and the ionization potential IPt1 of the charge transporting layer is within the range of -0.1 to +0.1 eV.