STRUCTURAL MEMBER

A structural member includes a first member, a second member, and a restricting portion. The first member includes a top plate, vertical walls, flanges, and ridge portions. The second member includes a top plate, vertical walls, flanges, and ridge portions. The vertical walls of the second member are disposed along the vertical walls of the first member inside of the vertical walls. The flanges of the second member are joined to the flanges of the first member, respectively. The restricting portion is provided between the vertical walls of the second member. The restricting portion restricts deformation in which portions of the vertical walls of the first member close to the flanges approach each other.