A flame-retardant resin composition comprises 10 to 300 parts by weight of a flame retardant (B) and 1 to 200 parts by weight of an inorganic filler (C) (a glass fiber and/or a glass flake), relative to 100 parts by weight of a base resin (A). The flame retardant (B) comprises a polyphenylene oxide-series resin and/or a polyphenylene sulfide-series resin (B1), a phosphoric ester (B2), and a nitrogen-containing cyclic compound (B3) (for example, a polyphosphate of an amino group-containing triazine compound). The inorganic filler (C) has been treated with a surface-treatment agent or sizing agent containing a novolak epoxy resin. Such a resin composition is useful for obtaining a shaped article which has been inhibited from dripping and to which flame retardancy is highly imparted.