The purpose of the present invention is to provide an organic EL display device which is free from decrease of emission luminance or pixel shrinkage and has excellent long-term reliability. An organic EL display device according to the present invention is characterized in that: an insulating layer formed on a first electrode is a cured film obtained from a positive photosensitive resin composition that contains (A) an alkali-soluble resin, (B) an o-quinonediazide compound and (C) an organic solvent; and the molar ratio S/C as obtained in measurement of a cross-sectional surface of the cured film is from 0.003 to 0.008 (inclusive).