A resin composition suitable for manufacturing a laser light transmission-side molded article; and a laser light transmission-side molded article are disclosed. A method for improving the laser light transmission properties of a resin composition molded article is also disclosed. The resin composition includes: 100 parts by mass of a polyalkylene terephthalate resin (A); 10-100 parts by mass of a polycarbonate resin (B); 0.1-3 parts by mass of a carbodiimide compound (C); 0-100 parts by mass of an inorganic filler (D); and an inorganic phosphorus compound (E). The method includes blending 0.1-3 parts by mass of a carbodiimide compound (C) in a resin composition including 100 parts by mass of a polyalkylene terephthalate resin (A), 10-100 parts by mass of a polycarbonate resin (B), 0-100 parts by mass of an inorganic filler (D), and an inorganic phosphorus compound (E).