NOVELTY - A photocatalyst coating component has photocatalyst layer, and intermediate layer provided between photocatalyst layer and base material. The intermediate layer comprises silicone modified resin and organic anti-fungal agent. The photocatalyst layer contains 1-20 mass parts of photocatalyst particles, 70-99 mass parts of inorganic oxide particles, dried product of 0-10 mass parts hydrolysable silicone, copper and silver. The total content of photocatalyst particles, inorganic oxide particles and silica equivalent amount of hydrolysable silicone is 100 mass parts.    USE - Photocatalyst coating component is used for exterior material (claimed). Uses include but are not limited to building materials, window frame, window glass, structural component, machinery, dustproof cover, traffic sign, display device, sound insulation wall for road, railways, bridge and guard rail, solar cell cover, etc.    ADVANTAGE - The photocatalyst coating component has excellent weather resistance, strength, anti-algae property, degradability of toxic substance, stain resistance, and mildew-proof capability.    DETAILED DESCRIPTION - A photocatalyst coating component has photocatalyst layer provided on the base material, and intermediate layer is provided between photocatalyst layer and base material. The intermediate layer comprises silicone modified resin and an organic anti-fungal agent. The photocatalyst layer contains 1-20 mass parts of photocatalyst particles, 70-99 mass parts of inorganic oxide particles, dried product of 0-10 mass parts hydrolysable silicone in silica conversion, copper and silver. The total content of photocatalyst particles, inorganic oxide particles and silica equivalent amount of the hydrolysable silicone is 100 mass parts. An INDEPENDENT CLAIM is included for photocatalyst coating liquid, which contains solvent, 1-20 mass parts of photocatalyst particles, 70-99 mass parts of inorganic oxide particles, 0-10 mass parts of hydrolysable silicone in silica conversion, copper and silver, such that their total content is 100 mass parts.