A granular photocatalytic material in the form of pellets or tablet is produced by compressing a photocatalyst mixture containing photocatalytic particles and a filler in air, a vacuum, or an inert gas at a temperature of 0 to 200 C., a pressure of 500 to 6000 kg/cm², and a pressing time of 0.01 to 60 seconds. An alkali slurry is applied on the surface of the granular photocatalytic material. A method of restoring a function of granular photocatalytic material comprises washing the surface of the granular photocatalytic material with the slurry or an alkali solution of sodium hydroxide An apparatus for decomposing and removing toxic organic matter comprises a means of bringing the granular photocatalytic material into contact with the toxic organic matter in a liquid or air, and a means of irradiating the granular photocatalytic material with light having a wavelength of 400 nm or less.