PURPOSE: To obtain a plate-shaped composite material high in strength and suitable for mass production by laminating a glass plate and a plate-shaped laminating material through an adhesive supporting sheet having a thermoplastic adhesive on both surfaces thereof.

CONSTITUTION: For example, a glass plate is used as a laminating material A and this laminating material A and a glass plate C are laminated through a film-shaped adhesive B to form a plate-shaped composite material E. The film-shaped adhesive B has a three-layered structure wherein thermoplastic adhesive layers are laminated to both surfaces of a thin core sheet being an adhesive supporting sheet. By using the film-shaped adhesive B having the three-layered structure, this adhesive B is extremely tough and becomes easy to handle and, by merely coating the laminating material A with the film-shaped adhesive B, adhesive applying work can be performed.