PURPOSE: To increase a surface area and to improve moisture permeability or air permeability by spreading a ceramics powder having function absorbing and emitting light and heat on a base material as a composition of synthetic resins to form a coated sheet and applying wrinkle imparting processing to this composite sheet.

CONSTITUTION: An acrylic emulsion is applied to wall material paper as an under coating agent by gravure coating technique and dried. Next, a fine powder of a transition metal oxide compound, a fine powder of titanium oxide and a viscosity controller are mixed with a hard type acryic emulsion to prepare a pasty coating compound which is, in turn, applied to the base material subjected to under coating processing and dried to form a film-like layer on the base material. This composite sheet-like article is gripped so as to provide a predetermined gap by grippers and said gap is narrowed and the grippers are shaken to perform processing like manual rubbing to apply wrinkle imparting processing to said article. By this method, the strain forming parts of the surface of the film-like layer generate fine damages and cracks to increase the surface area of the composite sheet-like article.