Provided is a film-forming composition containing organic monomers represented by formula (A) that are capable of providing triazine ring-containing polymers, crosslinking agents, and linear polymers, which contain a repeating unit structure represented by formula (1). Thus, a film-forming composition that is suitable as an embedding material can be provided, said film-forming composition: including triazine ring-containing polymers that are capable of achieving, by polymer alone, high heat resistance, high transparency, a high refractive index, high solubility and low volume shrinkage; and is capable of minimizing occurrences of cracks when embedding films are manufactured. Furthermore, a solvent-free film-forming composition that does not contain any solvents conducive to organic electroluminescent film degradation, can be cured at a low temperature, and is suitable for forming top-emission type organic electroluminescent elements, can be provided.