To provide a photocatalyst that exhibits high activity in a photocatalytic reaction including water molecules and the like as reactants, and a method for producing hydrogen using the photocatalyst.

The photocatalyst contains tubular nanocarbons which have a six-membered ring structure of carbon in an outer shell thereof and open at least one end thereof, and a photocatalyst component which generates electrons and electron holes by light irradiation. In the method for producing hydrogen, the photocatalyst is made to act on hydrogen-containing compounds, such as alcohols, or their aqueous solution.