The thermosetting resin composition includes, for example, a composition comprising a base resin such as an acryl resin, a polyester resin, an alkyd resin, a fluororesin, a urethane resin and a silicon-containing resin each having a cross-linkable functional group such as a hydroxyl group, a carboxyl group, a silanol group and an epoxy group and a cross-linking agent such as a melamine resin, a ur