The present invention is to provide a thermoplastic resin composition capable of providing a molded article that is excellent in capability of shielding millimeter waves. A thermoplastic resin composition for a molded article having a capability of shielding millimeter waves, containing (A) a thermoplastic resin and (B) carbon long fibers having a fiber length of from 3 to 30 mm in an amount of from 0.5 to 5% by mass. A molded article obtained from the composition is excellent in capability of shielding millimeter waves and can be used as a protective member for a transmitting and receiving antenna of a millimeter wave radar.