Surface functionalization of titanium metal is very attractive for bio‐ and environmental applications. This is because titanium metal is very stable and has a good biocompatibility. In this case, surface roughness and crystalline structure are important factors for obtaining effective characteristics. Titanium metal is usually covered with a surface passive film of thermodynamically stable rutile‐TiO2 that grows as the heat treatment temperature in air increases. On the other hand, to obtain an anatase‐TiO2 surface layer on titanium metal, we must employ specific treatments such as our previous method, which uses a silica‐coexisting heat‐treatment process. In this paper, the relationship between the fine structure formed on the titanium metal and the surface hydrophilic property was clarified, and the potential for the bio‐application was discussed. The formed anatase‐TiO2 coexisting with silica exhibited improved biocompatibility with good apatite formation.