A condensed phosphate containing an alkaline earth metal is caused to be present on the surface of titanium dioxide fine particles, and as a result, the condensed phosphate is firmly coupled with the fine particles and is barely liberated from the surface of the fine particles into a medium such as a binder or a resin. As a result, photo-functional particles exhibiting durability and dispersion stability are obtained. By use of the photo-functional particles, a powder and a slurry exhibiting excellent photo-functional property, durability, dispersion stability, and hydrophilicity are produced. In addition, by use of the powder and slurry, a polymer composition, a coating agent, a photo-functional formed article, and a photo-functional structure are produced.