To provide a structural member having a small thickness with a small amount of a material, an excellent rigidity and high general purpose properties.

The structural member 107 is constituted as one plate-like member by superposing a first plate member 102 constituted by a metal thin plate and having a plurality of truncated pyramidal protrusions arranged in a zigzag state and a second plate member 103 similarly constituted by a metal thin plate having a plurality of truncated pyramidal protrusions arranged in a zigzag state so that ends of the protrusions provided on the plates 102, 103 are not superposed in opposed states, clamping contact parts of the members 102, 103, and laminating them.