The thermoplastic resin composition contains (A) a polyamide, (B) a polyphenylene ether, and (C) a compatibilizer. When the thermoplastic resin composition is molded into a specimen, a continuous phase containing the polyamide (A) and a dispersed phase containing the polyphenylene ether (B) are formed in the specimen, and E-20 represents a mean ellipticity of the dispersed phase in region I extending from a surface of the hinge portion to a depth of 20 μm in the thickness direction, and E-mid represents a mean ellipticity of the dispersed phase in region II extending from a distance, measured along the thickness direction from the surface, equal to 48% of the thickness to a distance, measured along the thickness direction from the surface, equal to 52% of the thickness, the following formula (1) is satisfied: 4.0≤(E-20)/(E-mid)  (1).