A flameproof thermoplastic resin composition of the present invention comprises (A) a base resin comprising 40 to 95% by weight of a rubber modified styrene-containing resin (a1) composed of 20 to 100% by weight of a styrene-containing graft copolymer resin (a11) and 0 to 80% by weight of a styrene-containing copolymer resin (a12), and 60 to 5% by weight of polyphenylene ether resin (a2); (B) 2 to 40 parts by weight of a styrene-acrylonitrile copolymer containing 5 to 18% by weight of acrylonitrile per 100 parts by weight of the base resin; (C) 5 to 30 parts by weight of an aromatic phosphoric acid ester compound having a melting point of more than 90° C. per 100 parts by weight of the base resin; and (D) 3 to 30 parts by weight of a phenolic resin per 100 parts by weight of the base resin. The flameproof thermoplastic resin composition may further comprise 0 to 30 parts by weight of an anti-dripping agent, an impact modifier, a plasticizer, a heat stabilizer, an oxidation inhibitor, a light stabilizer, a compatibilizer, pigments, dyes and/or inorganic fillers on the basis of 100 parts by weight of the base resin.