The present invention provides a resin composition which is excellent in moisture and heat resistance, thermal stability, rigidity, surface impact properties and chemical resistance. The resin composition includes, based on a total of 100 parts by weight consisting of (A) 30 to 99 parts by weight of a resin (component A), which is composed of 10 to 100 wt % of a polycarbonate-polydiorganosiloxane copolymer resin (component A1) and 0 to 90 wt % of an aromatic polycarbonate resin (component A2), and (B) 1 to 70 parts by weight of a polyester resin (component B), (C) 10 to 50 parts by weight of a filler (component C) which is surface-treated with a silane coupling agent having an alkyl group, wherein the content of rubber-like polymer is 3 parts by weight or less.