A resin composition is provided. The resin composition comprises an acrylonitrile butadiene styrene resin, a polystyrene resin, a polycarbonate resin, and a phosphorus compound. The amount of the polystyrene resin is equal to or greater than the amount of the acrylonitrile butadiene styrene resin. The amount of the polycarbonate resin is from 70 to 90 parts by mass with respect to 100 parts by mass of all the resins. The phosphorus compound contains a phosphazene compound, and the amount of the phosphazene compound is from 0.1 to 4.0 parts by mass with respect to 100 parts by mass of all the resins.