To provide an undercoat layer having satisfactory adhesion to an electrically conductive substrate and a photosensitive layer and giving a satisfactory image due to high chargeability and low potential in a light part in an environment at 5-35°C and 20-85% RH and having stable chargeability and low potential in a light part even after a repetition test.

In this electrophotographic org. photoreceptor consisting of an electrically conductive substrate, an undercoat layer and a photosensitive layer, the undercoat layer is made of N-(alkoxymethyl)nylon as copolymerized nylon based on 12-nylon or a mixture of nylon with alcohol-soluble copolymerized nylon. The rate of N-alkoxymethylation is 1 to <15% for nylon as a whole and the thickness of the undercoat layer is ≤1.5μm.