Provided is a PAS resin composition with which molded articles having excellent high- and low-temperature impact properties can be obtained and which can be highly inhibited from leaving mold deposits when molded and is suitable for use in insert molding. Also provided is an insert-molded article obtained using the resin composition. The PAS-derived resin composition comprises a PAS resin having carboxylic terminal groups and an olefin-derived copolymer, wherein the olefin-derived copolymer comprises units of an α-olefin, a glycidyl ester of an α,β-unsaturated acid, and an acrylic ester as comonomer units, the PAS resin has a number average molecular weight of 1,000-10,000, and the content of the comonomer units derived from the glycidyl ester in the resin composition is 0.08-0.20 mass %, the ratio of the content of the comonomer units derived from the glycidyl ester (mmol/kg) to the amount of the carboxylic terminal groups (mmol/kg) being 0.35-1.00.