Surface functionalization of titanium metal is of great interest, especially as the conversion of the surface passive film into objective functional film can be widely used in bio‐ and environmental applications. However, since the surface passive film is very stable, the functionalization (such as conversion into photocatalytic anatase‐TiO2) has been performed using relatively complicated processes, for example, hydrothermal reaction and anodic oxidation. This is because direct oxidation of titanium metal only leads to thermodynamic formation of octahedral‐rutile‐TiO2 in the entire temperature region, while chemical synthesis using precursors can easily produce tetrahedral‐anatase‐TiO2 at 600°C or less. Here, we report a simple process for the direct formation of photocatalytic anatase‐TiO2 on titanium by simple oxidation. In the first step in our process, titanium is treated with a reducing agent to create a surface titaniumhydride layer. After that, the treated titanium covered with titaniumhydride is immerged in aqueous silica; subsequent calcination at 900°C (specific temperature) in air effectively generates the surface anatase‐TiO2 layer. This is because the covered tetrahedral‐silica stabilizes the anatase structure that is formed. The covered silica is easily removed by quenching in water to reveal the photocatalytic surface layer composed of anatase‐TiO2.