There is provided a film-forming composition for forming a film that covers a substrate and exhibits good electrical insulation properties, heat resistance, and solvent resistance after heating at a low temperature. A film-forming composition including a polymer (A) containing a unit structure of Formula (1): (wherein T1 is an arylene group or a combination of an arylene group with T0, T0 is an alkylene group, a fluorinated alkylene group, a carbonyl group, a sulfonyl group, or a combination thereof, R1 is a carboxyl group, an amino group, or an imino group, and n1 is an integer of 1 to 6), and a compound (B) having at least two isocyanate groups or blocked isocyanate groups. The polymer (A) is a polymer containing a unit structure of Formula (1) or a structure (A-1) having a combination of the unit structure of Formula (1) with a unit structure of Formula (2):