To provide a closed section member having excellent twist fatigue, capable of achieving fatigue characteristics expected for strength of a steel member.

The length direction of the member is set to be perpendicular to the rolling direction of the steel member, and a bend part less than five times the plate thickness of the bend radius is formed in this closed section member for an automobile. The closed section member is suitable as a torsion beam of a suspension in an automobile, for example. Since the length of the member is perpendicular to the rolling direction of the steel member, generation of fatigue cracking at the bend part can be prevented, thereby twist fatigue characteristics are improved.