Disclosed are methods for producing films of a composite comprising a metal oxide in combination with one or more other oxides or metals as a third component, or a composite comprising a metal oxide doped with metal ions as a third component, methods for producing titanium oxide coating layers having transparency, low peeling property and weather resistance, which are comparable to or even more excellent than those of conventional ones, as well as surface hardness comparable to that of coating films produced by using sintering, on plastic substrates, and methods for producing titanium oxide which exhibits photocatalytic activity even with light of visible light range. These methods do not require a treatment at a high temperature. Also disclosed are anti-fogging materials excellent in anti-fogging property, which have transparency, peeling property and weather resistance, which are comparable to or even more excellent than those of conventional ones, as well as surface hardness comparable to that of coating films produced by using sintering, and have excellent photocatalytic function of titanium oxide and a reflectance lower than titanium oxide.