The invention relates to an electrophotographic photosensitive member and an image forming device using same. Disclosed is the electrophotographic photosensitive member having excellent wear resistance, wherein the photosensitive layer of the photosensitive member contains a polyester resin having a repeating unit represented by the formula (1) below and a hydrazone compound (1). (In the formula (1), Ar<1>-Ar<4> independently represent an optionally substituted arylene group; X<1> represents a divalent group (including a single bond); and X<2> represents a divalent group having an atomic number of 3 or less (including a single bond)).