To provide a flame-retardant resin composition having excellent scuff resistance, flame retardance, processing stability, etc.

The flame-retardant resin composition is obtained by compounding 100 pts. wt. of a resin component (A) with an aluminum hydroxide (B) in an amount of 110-160 pts. wt. and an iron compound (C) in an amount of 1-100 pts. wt, based on 100 pts. wt. of the resin component (A), respectively. The resin component is composed of a magnesium ionomer (A1) of an ethylene-unsaturated carboxylic acid copolymer having 10-35% degree of neutralization and the melt flow rate at 190°C under 2,160 g load within the range of 1-500 g/10 min or the (A1) and another thermoplastic resin (A2) in an amount of equal weight or less based on the (A1).