In order to provide a resin composition containing a lactic acid resin, and a molded article obtained from this resin composition which impart flame retardance to the resin composition and suppress a reduction in the molecular weight, use is made of a flame-retardant resin composition which contains a resin composition of which the major component is a lactic acid resin, and a surface-treated metallic hydroxide, wherein the surface-treated metallic hydroxide is added by 50-150 parts by mass per 100 parts by mass of the lactic acid resin.