A thermoplastic resin composition of the present invention contains: a first aromatic vinyl-based resin, which is a copolymer of an aromatic vinyl-based monomer and a maleic acid anhydride; a second aromatic vinyl-based resin, which is a copolymer of an aromatic vinyl-based monomer, a maleic acid anhydride, and a maleimide-based monomer represented by chemical formula 1; a rubber-modified vinyl-based graft copolymer; and a reinforcing filler. The thermoplastic resin composition is excellent in view of heat resistance, rigidity, dimensional stability, and the like.