The invention provides an electrophotographic photoreceptor, a process cartridge, and an image forming apparatus. An electrophotographic photoreceptor includes a conductive substrate; a single-layer photosensitive layer that is provided on the conductive substrate and includes a binder resin, a charge generation material, a hole transport material, and an electron transport material, wherein a half decay exposure during positive charging is less than or equal to 0.18 muJ/cm2, and a half decay exposure during negative charging is 2 to 12 times the half decay exposure during positive charging. By using the electrophotographic photoreceptor, the superposed image can be inhibited.