A method for manufacturing an organic electroluminescent element comprising, in the following order, an anode, a light-emitting layer, an electron injection layer, and a cathode, the method comprising the steps of: forming the anode; forming the light-emitting layer; forming the electron injection layer; and forming the cathode, wherein the step comprises (i) applying an application liquid comprising an ionic polymer to form a thin film, (ii) heating the thin film formed, (iii) storing a partially finished organic electroluminescent element obtained in (ii), thereafter, (iv) heating the thin film again in an atmosphere in which the volume proportion of nitrogen is 90% or less and the volume proportion of oxygen is from 10% to 30%, and the ionic polymer comprises a structural unit represented by Formula: wherein R 13 represents a (1+m11+m12) valent organic group; Q 1 represents a divalent organic group; Q 3 represents a divalent organic group; Y 1 represents -CO 2 -, -SO 3 -, -SO 2 -, -PO 3 2- or -B(R a) 3 -; M 1 represents a metal cation or an ammonium cation optionally having a substituent; Z 1 represents F -, Cl -, Br -, I -, OH -, R a SO 3 -, R a COO -, ClO -, ClO 2 -, ClO 3 -, ClO 4 -, SCN -, CN -, NO 3 -, SO 4 2-, HSO 4 -, PO 4 3-, HPO 4 2-, H 2 PO 4 -, BF 4 - or PF 6 - R a represents a C 1-30 alkyl group or a C 6-50 aryl group; Y 3 represents -CN or a group represented by any one of Formulae to: -O-(R'O) a3 -R" -S-(R'S) a4 -R" -C(=O)-(R'-C(=O)) a4 -R" -C(=S)-(R'-C(=S)) a4 -R" -N{(R') a4 R"} 2 -C(=O)O-(R'-C(=O)O) a4 -R" -C(=O)O-(R'O) a4 -R" -NHC(=O)-(R'NHC(=O)) a4 -R" wherein R' represents a divalent hydrocarbon group optionally having a substituent; R" represents a hydrogen atom, a monovalent hydrocarbon group optionally having a substituent, -COOH, -SO 3 H, -OH, -SH, -NR c 2, -CN, or -C(=O)NR c 2; R'" represents a trivalent hydrocarbon group optionally having a substituent; a3 represents an integer of 1 or more; a4 represents an integer of 0 or more; R c represents a C 1-30 alkyl group optionally having a substituent or a C 6-50 aryl group optionally having a substituent; and when each of R', R", and R"' is present in plurality, they may be the same as or different from each other; n1 represents an integer of 0 or more; a1 represents an integer of 1 or more and b1 represents an integer of 0 or more, with the proviso that a1 and b1 are selected so that the electric charge of the group represented by -(Q 1) n1 -Y 1 M 1) a1 (Z 1) b1 becomes 0; n3 represents an integer of 0 or more; m11 and m12 each independently represent an integer of 1 or more; and when each of R 13, m11, m12, Q 1, Q 3, Y 1, M 1, Z 1, Y 3, n1, a1, b1, and n3 is present in plurality, they may be the same as or different from each other. forming the anode; forming the light-emitting layer; forming the electron injection layer; and forming the cathode, R 13 represents a (1+m11+m12) valent organic group; Q 1 represents a divalent organic group; Q 3 represents a divalent organic group; Y 1 represents -CO 2 -, -SO 3 -, -SO 2 -, -PO 3 2- or -B(R a) 3 -; M 1 represents a metal cation or an ammonium cation optionally having a substituent; Z 1 represents F -, Cl -, Br -, I -, OH -, R a SO 3 -, R a COO -, ClO -, ClO 2 -, ClO 3 -, ClO 4 -, SCN -, CN -, NO 3 -, SO 4 2-, HSO 4 -, PO 4 3-, HPO 4 2-, H 2 PO 4 -, BF 4 - or PF 6 - R a represents a C 1-30 alkyl group or a C 6-50 aryl group; Y 3 represents -CN or a group represented by any one of Formulae to: -O-(R'O) a3 -R" -S-(R'S) a4 -R" -C(=O)-(R'-C(=O)) a4 -R" -C(=S)-(R'-C(=S)) a4 -R" -N{(R') a4 R"} 2 -C(=O)O-(R'-C(=O)O) a4 -R" -C(=O)O-(R'O) a4 -R" -NHC(=O)-(R'NHC(=O)) a4 -R" R' represents a divalent hydrocarbon group optionally having a substituent; R" represents a hydrogen atom, a monovalent hydrocarbon group optionally having a substituent, -COOH, -SO 3 H, -OH, -SH, -NR c 2, -CN, or -C(=O)NR c 2; R'" represents a trivalent hydrocarbon group optionally having a substituent; a3 represents an integer of 1 or more; a4 represents an integer of 0 or more; R c represents a C 1-30 alkyl group optionally having a substituent or a C 6-50 aryl group optionally having a substituent; and when each of R', R", and R"' is present in plurality, they may be the same as or different from each other; n1 represents an integer of 0 or more; a1 represents an integer of 1 or more and b1 represents an integer of 0 or more, with the proviso that a1 and b1 are selected so that the electric charge of the group represented by -(Q 1) n1 -Y 1 M 1) a1 (Z 1) b1 becomes 0; n3 represents an integer of 0 or more; m11 and m12 each independently represent an integer of 1 or more; and when each of R 13, m11, m12, Q 1, Q 3, Y 1, M 1, Z 1, Y 3, n1, a1, b1, and n3 is present in plurality, they may be the same as or different from each other.