A photocatalyst, Ag In W2O8, with a layered structure was synthesized. The physical and photophysical properties of the photocatalyst were characterized by XRD, BET measurement, UV-visible diffuse reflectance, and photoluminescence, respectively. The photocatalytic properties of the photocatalyst for H2 evolution with Pt cocatalyst from CH3OH/H2O solution and O2 evolution from Ag NO3 solution were observed under UV and visible light irradiation. The Ag In W2O8 photocatalyst presented not only the activity of O2 evolution but also the activity of H2 evolution. Also the photocatalyst showed the ability to evolve H2 from pure water under full arc irradiation. On the basis of all the results, the band structure of the photocatalyst was discussed.