Plastics were recovered from Al containing laminated film by the thermal treatment in limonene, and in the case of the IC package and waste tire separation of organic materials and inorganic parts was attained by the thermal treatment in high temperature water and organic solvents. Foamed phenol resin was solubilized by the treatment in organic solvent at relatively mild temperature, and the production of monomeric materials such as phenol and cresols were confirmed.