The present invention relates to a thermoplastic resin composition which contains a thermoplastic polymer (A) containing a glutaric anhydride-containing component shown in the following general formula (1), where R1 and R2 are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a rubber-containing polymer compound (B), and satisfies the following conditions of (I) and/or (II), (I) a total light transmittance per 2 mm of the thickness of the thermoplastic resin composition is more than 90%, (II) a weight-average molecular weight of a thermoplastic polymer (A) is from 30,000 to 150,000 and a glass transition temperature is at least 130° C. According to the present invention, a thermoplastic composition having high heat resistance, superior mechanical properties, colorless transparency, optical isotropy and moldability, as well as solvent resistance, is provided.