NOVELTY - An organic electroluminescent element has a positive hole injection layer and a light emitting layer provided between electrodes such as anode and cathode. The positive hole injection layer contains conductive polymer (A) having acidic radical and specific polymer (B) having acidic radical.    USE - As backlight for sheet-like light source, segment display device, dot matrix display device and liquid crystal display (all claimed) used for computer, television, portable terminal, mobile telephone, car navigation and view finder of video camera.    ADVANTAGE - The organic electroluminescent element has excellent durability and luminous efficiency.    DETAILED DESCRIPTION - An organic electroluminescent element has a positive hole injection layer and a light emitting layer provided between electrodes such as anode and cathode. The positive hole injection layer contains conductive polymer (A) having acidic radical and polymer (B) having acidic radical of formula: -(-Ar1-X1-)m-, -(-Ar2-X2-Ar3-X3-)m- or -(-Ar4-X4-Ar5-X5-Ar6-X6-)m-.    m=integer greater than or equal to 10;    Ar1-Ar6=bivalent aromatic group optionally substituted by 1-10C alkyl, 1-10C alkoxy, 6-10C aryl or 6-10C aryloxy group, and acid radical is bonded to at least one of Ar1, Ar2 and Ar3, or Ar4, Ar5 and Ar6 directly or through coupling group;    X1-X6=-O-, -S-, -SO-, -SO2-, -CO-, -CR'"R'"- or direct bond;and    R'"=1-10C alkyl, 1-10C alkoxy, 6-10C aryl or 6-10C aryloxy group.    INDEPENDENT CLAIMS are included for the following:    (1) sheet-like light source, which uses the organic electroluminescent element;    (2) segment display device, which uses the organic electroluminescent element;    (3) dot matrix display device, which uses the organic electroluminescent element;    (4) liquid crystal display, which has the organic electroluminescent element as a back light;    (5) composition (C1), which contains the conductive polymer (A) having acidic radical and polymer (B) having acidic radical;    (6) thin film, which contains the composition (C1) and has thickness of 0.01-5 microns;    (7) electroconductive thin film, which contains the composition (C1) and has electroconductivity of 1x10-6 S/cm;    (8) antistatic thin film, which contains the composition (C1);    (9) organic-semiconductor thin film, which contains the composition (C1);    (10) solar cell, which contains the composition (C1); and    (11) electric-charge injection property thin film of light-emitting element, which contains the composition (C1).