TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The water-insoluble inorganic compound contains silica compound, silica alumina compound, aluminum compound, calcium compound, nitride and coal ash, and phyllosilicate mineral. The phyllosilicate mineral is non-swelling clay mineral. The metal film used as heat-transfer layer is aluminum film or copper film. The non-swelling clay mineral is chosen from talc, kaolin, pyrophyllite and non-swelling mica.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The dispersion medium is chosen from N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, and sulfolane.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The thermal radiation film comprises an insulating layer laminated on other surface of heat-transfer layer. The heat resistant synthetic resin is polyimide resin or polyamidoimide resin. The substrate comprises glass, polyethylene terephthalate, polyimide, polyethylene, or polypropylene. Preferred Properties: In cross-cut method test of thermal radiation layer, based on JIS K5600, the adhesive classification with the metal film used as heat-transfer layer is 0-2. In UL94 specification VTM test, the combustible classification of thermal radiation layer is VTM-0, and the thickness of thermal radiation layer is 100 mu m or less when combustible classification is set to VTM-0. The thickness of the thermal radiation layer is 20-100 mu m. The thickness of heat-transfer layer is 10-1000 mu m. In the bending-resistant test by the cylindrical mandrel method based on JIS K5600-5-1(1999) the mandrel diameter at the time of crack arising in the thermal radiation layer is 10 mm or less. The thermal radiation film has water-vapor permeability less than 0.01 g/m2.day in 90% relative humidity and at 40 degrees C. The thickness of the dispersion liquid expanded on metal film is 30 mu m or more. The thickness of dispersion liquid expanded on substrate is 30 mu m or more. Preferred Process: The cooling temperature at the time of installing in the upper surface of ceramic heater (2.4 cm2 and 0.5-1.5 mm in thickness) which input 3-W electric power and generate heat in the ceramic heater and the same area is 15 degrees C or more. The temperature at the time of removing dispersion medium from the dispersion liquid is 20-150 degrees C. During hot pressing of metal film on the film, the temperature is 50-200 degrees C and pressure is 10-100 kgf/cm2.