Method for manufacturing organic EL element including anode, hole injection layer, buffer layer, light-emitting layer, and cathode, layered on substrate in the stated order, and banks defining a light-emission region, and having excellent light-emission characteristics, due to the hole injection layer having excellent hole injection efficiency, being a tungsten oxide layer including an oxygen vacancy structure, formed under predetermined conditions to have an occupied energy level within a binding energy range from 1.8 eV to 3.6 eV lower than a lowest binding energy of a valence band, and after formation, subjected to atmospheric firing at a temperature within 200° C.-230° C. inclusive for a processing time of 15-45 minutes inclusive to have increased film density and improved dissolution resistance against an etching solution, a cleaning liquid, etc., used in a bank forming process.