PURPOSE: To effectively utilize natural resources by effectively utilizing old paper and reducing the wastefulness in the treatment of dust by mounting a composite panel formed by providing slits 6 to paper in a lath state and filling the slitted paper with a resin in such a state that the slitted paper is stretched in the direction crossing the slitting direction and the surface plates laminated so as to hold the composite panel therebetween.

CONSTITUTION: Slits 6 are provided to the entire surface of paper 5 in a lath state. Since these slits 6 are provided without forming holes 9 by punching, there is such a merit that no scrap is generated. The paper is stretched in the direction crossing the slitting direction and a polyurethane resin containing isocyanurate is applied to the surface and rear of the paper by spraying or a roll coater. Many papers are superposed so as to cross the slits mutually and surface plates 3, 4 formed by thinly slicing natural wood are placed on the surface and rear of the superposed one and the whole is sealed in a mold to be heated under pressure. Composite panels 1, 2 of the papers and a foamed resin are formed by the foaming action and bonding/curing action of the polyurethane resin 8 and simultaneously bonded along with the surface plates to form an integrated laminated panel.