PROBLEM TO BE SOLVED: To obtain a fluororesin film which efficiently diffuses light and has ultraviolet screening properties by dispersing composite particles each having a structure of, from the outermost layer, amorphous silica-cerium oxide-base pigment in a fluororesin. SOLUTION: Particles formed by coating base pigment particles selected from among silica, talc, and mica and having an average size of 1-3μm with an insoluble cerium compd. and then with an amorphous silica are baked at 200-1,000 deg.C and if necessary treated with a surface treating agent to give composite particles each having a structure of, from the outermost layer, amorphous silica-cerium oxidebase pigment and adjusted to a methanol hydrophobization degree of 40-75%. The objective fluororesin film is obtd. by dispersing 0.4-5 pts.wt. above-prepd. composite particles in 100 pts.wt. fluororesin (e.g. an ethylene-tetrafluoroethylene copolymer or a hxafluoropropylene- tetrafluoroethylene copoymer) and converting the resultant compsn. into a film.
