An impact resistance is improved and a molding shrinkage percentage is reduced. A thermoplastic resin composition contains: an impact-resistant styrene resin composition which contains polystyrene as a main component and a dispersed rubber phase and in which a volume fraction of the dispersed rubber phase 12 is less than 30%; dispersed phases of elastomer; and particles of a filler. The dispersed phases of the elastomer contains, as a main component, a styrene-butadiene copolymer serving as a linear copolymer constructed by a triblock consisting of a butadiene block and styrene blocks coupled with both ends of the butadiene block.