TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Fluid: Two or more types of fluids are used. At least 1 type of fluid includes titanium compound(s). Each fluid is merged in the thin film fluid. A dispersing agent is included in the fluid(s). At least 1 type of fluid is a reverse micellar solution obtained by adding a dispersing agent and water to an organic solvent. At least 1 type of fluid is non-aqueous solution containing a titanium compound, aqueous solution containing a titanium compound, or reverse micellar solution containing a titanium compound. The titanium compound is hydrolyzed in the thin film fluid, and titanium-dioxide ultrafine particles are obtained. At least one fluid includes a metallic compound containing the element formed into solid solution in titanium dioxide apart from the titanium compound. A pH adjuster and hydrogen peroxide are added to the fluid(s). A mixture and/or solid solution of glass containing silicon oxide and/or silicon, and substance containing complex oxide of silicon in hydrochloric acid, sulfuric acid, and/or nitric acid are added to the fluid. After adding acid containing chloride ions, such as hydrochloric acid, to the fluid, Broensted bases, such as nitrate ion and phosphate ion, are added to the fluid to which acid is added or to a different fluid. Aluminium oxide, zirconium oxide, silicon oxide, antimony oxide, stannic oxide, and/or zinc oxide, and organometallic compound, such as metal chelate compound and cyclic metal oligomer containing aluminum, zirconium, antimony, tin, zinc and/or titanium, or a metal alkoxide are added to the fluid. Apart from titanium compound, calcium carbonate and phosphoric acid, or hydroxyapatite are included in the fluid. Preferred Conditions: A mechanism (p1) which provides a preset pressure to the to-be-processed fluid, processing components (10,20), a rotational drive mechanism in which the components are rotated relatively, and two or more processing surfaces are used for manufacturing titanium-dioxide ultrafine particles. Each processing surface comprises a sealed flow path where the to-be-processed fluid of the specified pressure is poured. The to-be-processed fluids containing a reaction material are uniformly mixed and reacted between the processing surfaces. The processing component(s) is equipped with a pressure surface, and at least one portion of the pressure surface comprises the processing surface. By allowing the to-be-processed fluid of specified pressure pass between the surfaces rotated on a relative target, while the to-be-processed fluid forms a liquid film of preset thickness, the fluid is passed between the processing surfaces. A different supply-flow channel is provided. The processing surface(s) is equipped with an opening which leads to the supply-flow channel(s). The thin film fluid is formed by introducing fluid(s) sent from the supply-flow channel between the surfaces. An UV ray and ultrasonic energy are provided between the surfaces. Preferred Compound: The metallic compound is a metal alkoxide of aluminum, barium, magnesium, calcium, lanthanum, iron, silicon, zirconium, lead, tin, zinc, cadmium, arsenic, gallium, strontium, bismuth, tantalum, selenium, tellurium, hafnium, nickel, manganese, cobalt, sulfur, chromium, vanadium, germanium, lithium, or boron, or a metal salt. Preferred Property: The volume average particle diameter of the obtained titanium-dioxide ultrafine particles is 0.5-1000 nm.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The titanium compound is tetraalkoxy titanium, such as tetramethoxy titanium, tetraethoxy titanium, tetra-n-propoxy titanium, tetra-isopropoxy titanium, tetra-n-butoxytitanium, tetra-isobutoxy titanium, tetra-t-butoxytitanium, or its derivative(s), titanium tetrachloride, titanyl sulfate, titanium citrate, and/or titanium tetranitrate. Diols or triols chosen from ethyleneglycol, propyleneglycol, trimethyleneglycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, hexyleneglycol, octyleneglycol, glycerin, hexa-glycerol, and 1,2,6-hexanetriol are added to the fluid. Styrene, chlorostyrene, and/or methylstyrene, and acrylic acid and/or methylacrylate, methacrylic acid and/or methylmethacrylate are added to the fluid.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The dispersing agent is cellulose, such as starch, methylcellulose and ethylcellulose, polymer dispersion stabilizer, such as polyacrylimide, polyethyleneoxide and poly(hydroxystearic-acid-g-methylmethacrylate co- methacrylic acid) copolymer, non-ionic surfactant, anionic surfactant, amphiphilic surfactant, polyphosphoric acid, such as hexa-phosphoric acid, octa-phosphoric acid, tetra-phosphoric acid, and triphosphoric acid, polymeric organic acids, such as acetic acid, acrylic acid, and methacrylic acid, polyvinyl pyrrolidone, polyvinyl alcohol, and/or polymeric organic matter, such as sodium hexa-metaphosphate, or sodium diisooctylsulfosuccinate. Electrical charging controlling agent which is not a resin, such as metal complex of organic compound having a carboxyl group or a nitrogen-containing group, quaternary ammonium group or quaternary ammonium salt group-containing copolymer, sulfonic acid group or sulfonate group-containing copolymer, and/or carboxylic acid group or carboxylate salt group-containing copolymer, calixarene compound, metal-containing dye, and/or nigrosine are added to the fluid among the said fluids.