TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compound: The spherical inorganic particles are silica-type particles.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The spherical inorganic particles are surface treated using an organic compound.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The transparent film contains 30-99 weight% of fumaric-acid diester-type resin and 70-1 weight% of spherical inorganic particles. Preferred Compound: The fumaric-acid diester-type resin contains 50 mol% or more of fumaric-acid dieter-containing unit of formula: -CH-(C(=O)-O-R1)-CH-(C(=O)-O-R2)- (1).R1,R2=3-12C branched alkyl or cycloalkyl.Preferred Property: The transparent film has film thickness of 10-400 mu m, total light transmittance of 85% or more, wire coefficient of expansion of 80 ppm/ degrees C or less, and haze of 2 or less. EXAMPLE - Polyvinyl alcohol (24 g) having molecular weight of 2000 and saponification degree of 80%, tert-butyl peroxypivalate (50 g), distilled water (15.6 kg) and fumaric-acid diisopropyl (7.4 kg) were polymerized in presence of polymerization initiator under nitrogen atmosphere at 50 degrees C for 24 hours, to obtain fumaric-acid diester-type resin having number average molecular weight of 152000. (In weight parts) isopropanol silica sol (2000), 3-methacryloyloxypropyltrimethoxysilane (160) and water (100) were refluxed for 2 hours. Then, toluene (500) was added to the reaction mixture and azeotropy distillation of alcohol and water are carried out. Then, toluene (1000) was added and reacted at 110 degrees C for 4 hours. Then, toluene was distilled from the reaction mixture, to obtain spherical inorganic particles. The obtained fumaric-acid diester-type resin (80) was dissolved in a solution containing toluene (31), tetrahydrofuran (389), obtained spherical inorganic particles, pentaerythritol tetrakis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (0.3) and bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite (0.9) were mixed, to obtain a composition. The obtained composition was coated on a substrate and dried at 120 degrees C and 50 degrees C for 5 minutes and 10 minutes, respectively, to form a film having thickness of 80 mu m, total light transmittance of 91%, linear expansion coefficient of 74 ppm/ degrees C and haze of 0.7, and had excellent heat resistance even after heating at 200 degrees C for 1 hour.