connecting bolt 5 is directly attached to the vehicle frame attachment portion 2 by means of connecting bolt 5 the bumper member 1 is fixed to the front end of each of the vehicle frames 6 positioned toward the front and back of the vehicle not shown a sheet metal reinforcement frame 3 having a hat shaped cross section is fixed integrally with and projects into the inside of the frame attachment portion 2 thus forming a reinforced structure strengthening the bumper member 1 in other words the outer surface of the reinforcement frame 3 is covered with the resin composite material of the main bumper body 11 the front surface 7 of the frame 3 is facing and spaced from the front inner surface of bumper 11 at both sides 8 the approximately horizontal ribs 12 are formed in one piece with the bumper body 11 and approximately at right angles to the sides 8 in order to support both sides of the reinforcement frame 3 two side walls 9 see fig2 are formed in the frame 3 to offset the ribs 12 slightly left and right of the side of the frame 3 by means of this kind of construction the vehicle frame attachment portion 2 of the bumper 1 is integrally given high rigidity the rigidity of the reinforcement frame 3 which is formed on the inside of portion 2 is also improved also the reinforcement frame 3 allows the.