PURPOSE: To enable recession and protrusion patterns to be obtained without wasting materials and utilizing an adhesive agent, and also enable relief panels to be formed readily not so lowering the strength even in complicate recession and protrusion patterns in a relief panel with recession and protrusion patterns formed on the surface of board material of a synthetic resin foamed body.

CONSTITUTION: On the surface of board material 1 of a synthetic resin foamed body, notches 2 are made in the degree of not penetrating it, and a part of the area partitioned by the notches 2 is subjected to press-deformation to thus be recession parts 3, and other parts of the area are made into protrusion parts 4, thereby forming it into recession and protrusion patterns as a whole.