To provide a member which relates to a structural member having a sandwich structure and is usable for a support of a load in stead of, for example, a reinforcing steel plate.

The laminate plate of a composite structure includes, for example, two outer layers of a metal such as steel or the like and a middle core of an elastomer such as non-foamed polyurethane or the like. The elastomer has a modulus of larger than about 250 mega Pascal (MPa), a tensile strength of at least 20 MPa and a compression strength of at least 20 MPa. The bonding strength between the metal and the elastomer is at least 3 MPa. The laminate member of the composite structure works as a single member and bends asymmetrically as a whole when the member is loaded.