To provide a resin composition which is very high in rigidity, good in surface smoothness, thus excellent in external appearance, extremely high in flame retardancy, free from the evolution of a halogenic gas of high corrosiveness when combusting, excellent in working properties when extruded, excellent in moldability, small in corrosiveness to metals, and very little in gas evolution when extruded and molded.

The flame-retardancy strengthened polyamide resin composition comprises 100 pts.mass of a flame-retardant resin composition [(A)+(B)=100 mass%] including (A) 60-90 mass% of one or more kinds of polyamide resins and (B) 40-10 mass% of a halogen element-free phosphorus-based flame retardant, (C) 70-200 pts.mass of an inorganic filler and (D) 0.5-30 pts.mass of boehmite, wherein this flame-retardancy strengthened polyamide resin composition is such that (B) the halogen element-free phosphorus-based flame retardant comprises a phosphinate (b1) and/or a diphosphinate (b2).