Functional film, method for forming same, and organic electroluminescent element

A functional film comprising an aromatic compound, wherein

• the aromatic compound has a condensed or noncondensed 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring having four or more condensed aromatic ring groups containing not less than 14Π electrons, wherein three or more of the condensed aromatic ring groups containing not less than 14Π electrons are adjacent to one another as substituents, and wherein
• for the aromatic compound, when a film density value calculated by molecular dynamics calculation of NPT ensemble at 300 K is defined as an initial film density of the functional film comprising only the aromatic compound, and
• for the aromatic compound, when a film density value calculated by molecular dynamics calculation at 370 K is defined as a film density value after storage of the functional film at the temperature, the difference between the initial film density and the film density value after storage is 1% or less with respect to the initial film density.