PURPOSE: To form unevenness on the surface simply at a low cost, by a method wherein the uneven surface is formed by laminating a sheet material to the surface of a board and a filmy material is stuck close to the uneven surface.

CONSTITUTION: A board 4 where an uneven surface 5 is formed is formed by sticking board materials 3... on the surface 2 of a flat plate body 1 and a permeable film body 6 is put on the uneven surface 5. The filmy body 6 is heated under this state and sucked to a board side by a vacuum device. In this case, an adhesive agent is applied to the uneven surface 5. With this construction, patterning of the uneven surface 5 and various patterns and giving of high class feeling can be performed simply, inexpensively and respectively to the surface 2 of decorative plywood.