PURPOSE: To obtain the subject composition, containing an organozirconium compound in a polyimide-based precursor, excellent not only in heat and solvent resistances but also in adhesion to a substrate and suitable as an insulating film for semiconductor devices, a protective film, a material, etc., for optical transmission lines.

CONSTITUTION: This precursor composition contains (B) an organozirconium compound such as tributoxyacetylacetonatozirconium in (A) a polyimide-based precursor, e.g. a polyimide-based precursor, obtained by reacting a tetracarboxylic dianhydride, e.g. (trifluoromethyl)pyromellitic dianhydride with a diamine such as 4,4'-diaminodiphenyl ether in a polar solvent and having 1-30 imidation ratio. Furthermore, the content of the component (B) is preferably 0.005-5wt.% based on the component (A).