To provide a photocatalyst having high decomposition activity in which photocatalyst sticking or adsorption of dirt or the like onto a photocatalyst film is suppressed and a functional body using the same.

The photocatalyst film 2 contains a photocatalyst material comprising a hydrophobic metal compound as a constitutive element. Since the photocatalyst film 2 becomes hydrophobic, it becomes possible to suppress sticking or adsorption of dirt, gases or the like. Or, the surface of the photocatalyst film 2 is reformed and made hydrophobic by forming a protective film 4 having a thickness of ≤20 nm on the photocatalyst film 2. Further, the surface of the photocatalyst film 2 can be reformed by binding a metal oxide group through oxygen to at least a portion of its surface mainly comprising titanium oxide fine particles.