Disclosed is a thermosetting resin composition which enables to obtain a molded article that is excellent in mechanical properties, dimensional stability and heat resistance and is further capable of maintaining the shape of the article molded before curing even after the resin composition is cured. The thermosetting resin composition contains 100 parts by weight of a thermosetting resin and 1-100 parts by weight of an inorganic compound dispersed in the thermosetting resin, and the dispersion particle diameter of the inorganic compound is not more than 2 μm. Not less than 75% of the shape of an article molded before curing is maintained after the resin composition is cured. Also disclosed are a material for substrates and a film for substrates respectively composed by using such a thermosetting resin composition.