To simplify structure of a front side member and to improve impact energy absorbing efficiency in a collision.

In a front side member 1 provided with closed cross section structure, the first reinforcement 2 is arranged in a supporting part 1A for an engine, a suspension, and the like, and in front of the first reinforcement 2, the second reinforcement 3, which is integrally connected to the first reinforcement 2 so that its front end is protruded from the tip of the front side member 1, and is provided with a plate thickness thinner than that of the first reinforcement 2, is extended, so that an impact absorbing part 4 is formed of the front end projecting part in the second reinforcement 3. In this way, rigidity of the front side member 1 is gradually increased from the front side to the rear side.