A resin composition includes a polycarbonate resin, a polyethylene terephthalate resin, a glycidyl group-containing polyethylene copolymer, an organic phosphorus flame retardant, and a flame retardant antidrip agent, wherein the polycarbonate resin and the polyethylene terephthalate resin are contained in a specific content range, and wherein the glycidyl group-containing polyethylene copolymer is a polyethylene copolymer which is constituted with a glycidyl group-containing (meth) acrylic acid ester unit and an ethylene unit, in which a content of the glycidyl group-containing (meth) acrylic acid ester unit in the glycidyl group-containing polyethylene copolymer is in a range of 2% by weight to 20% by weight, and has a glass transition point of 0° C. or lower, or is a copolymer obtained by performing graft polymerization of a polymerizable vinyl monomer onto a main chain of the polyethylene copolymer constituted with a glycidyl group-containing (meth) acrylic acid ester unit and an ethylene unit.