ELECTROPHOTOGRAPHIC PHOTORECEPTOR, PROCESS CARTRIDGE, AND ELECTROPHOTOGRAPHIC DEVICE

To provide an electrophotographic photoreceptor that can reduce a residual potential and can reduce variations in bright part potential in short-term use at a higher level.SOLUTION: An electrophotographic photoreceptor has a support, a conductive layer, an undercoat layer, a charge generating layer, and a hole transport layer in this order. When the ionization potential of the conductive layer is defined as IPc, the IPc is 5.4 eV or more and 5.8 eV or less. When the ionization potential of the undercoat layer is defined as IPu, the IPu is 6.0 eV or more. The undercoat layer contains an electron transport compound and a compound (α). When the ionization potential of the compound (α) is defined as IPα, the IPc, the IPu, and the IPα satisfy the following relational expression (1). (1) IPu-IPc>IPα-IPc.SELECTED DRAWING: Figure 1 【課題】残留電位を低減し、短期使用における明部電位変動をさらに高度に低減可能な電子写真感光体を提供する。【解決手段】支持体、導電層、下引き層、電荷発生層及び、正孔輸送層をこの順に有する電子写真感光体であって、該導電層のイオン化ポテンシャルをＩＰｃとしたとき、該ＩＰｃが５．４ｅＶ以上５．８ｅＶ以下であり、該下引き層のイオン化ポテンシャルをＩＰｕとしたとき、該ＩＰｕが６．０ｅＶ以上であり、該下引き層が、電子輸送性化合物及び化合物（α）を含有し、該化合物（α）のイオン化ポテンシャルをＩＰαとしたとき、該ＩＰｃ、該ＩＰｕ及び該ＩＰαが、下記関係式（１）を満たす、ＩＰｕ－ＩＰｃ＞ＩＰα－ＩＰｃ（１）ことを特徴とする。【選択図】図１