To provide a photocatalyst coating composition forming a coating layer exhibiting a photocatalytic function, without extending a photocatalytic action onto a reverse face of an applied coating film.

In this photocatalyst coating composition, a granular photocatalyst metal oxide having a specific surface area of 250 m2/g or more is blended into a stable resin binder not affected by the photocatalytic action, and a blending ratio of the photocatalyst metal oxide is a volume ratio less than 20% to total volume of the photocatalyst metal oxide and a nonvolatile component of the resin binder.