PROBLEM TO BE SOLVED: To provide a method for highly productive, mass manufacturing nitrogen-doped titanium oxide powder having high photocatalytic activity when irradiated with a visible light and excellent UV light shield property especially when irradiated with a near range (UV-A) UV light which is close to a visible light among UV lights.SOLUTION: In the method, a titanium oxide powder is subjected to nitriding reduction in an ammonia gas atmosphere with a heating temperature of 800°C or over and 1200°C or under to manufacture a titanium oxynitride powder containing nitrogen of 8 mass% or over. This titanium oxynitride powder is subjected to oxidization in an oxidizing atmosphere with a heating temperature of 500°C or over and 700°C or under to manufacture a nitrogen-containing titanium oxide powder containing nitrogen at a rate of 0.2 mass% or over and 0.8 mass% or under and a lightness index L* value measured in accordance with CIE 1976 L*a*b* color space ( measurement light source C: color temperature 6774K) of 70 or over. When the manufactured nitrogen-containing titanium oxide powder is subjected to measurement as an aqueous dispersion containing the powder dispersed in a water at a concentration of 0.1 mass % in a glass cell having an optical path of 1 mm, its transmittance of a light at a wavelength of 400nm is 40% or under, and its transmittance of a visible light at a wavelength of 550nm is 40% or over and 85% or under.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2019,JPO&INPIT【課題】可視光を照射したときの光触媒活性が高く、かつ紫外線の中でも特に可視光に近い範囲（ＵＶ－Ａ）の紫外線を照射したときの紫外線遮蔽性に優れた窒素ドープ酸化チタン粉末を高い生産性で大量に生産できる。【解決手段】チタン酸化物粉末をアンモニアガス雰囲気下、８００℃以上１２００℃以下の加熱温度で窒化還元して窒素を８質量％以上含有する酸窒化チタン粉末を製造し、この酸窒化チタン粉末を酸化性雰囲気下、５００℃以上７００℃以下の加熱温度で酸化して、窒素を０．２質量％以上０．８質量％以下の割合で含有し、ＣＩＥ １９７６ Ｌ*ａ*ｂ*色空間（測定用光源Ｃ：色温度６７７４Ｋ）における明度指数Ｌ*値が７０以上である窒素含有型酸化チタン粉末を製造する。製造された窒素含有型酸化チタン粉末を粉末濃度０．１質量％で水に分散した水分散液を光路長１ｍｍのガラスセルに入れて測定をしたときに波長４００ｎｍの光透過率が４０％以下であり、波長５５０ｎｍの可視光透過率が４０％以上８５％以下である。【選択図】図１
