Glass material for carrying a photocatalyst, filter device using the same and light irradiating method

A photocatalyst filter comprising:

• a bundle of a plurality of elongate light guiding filter body members;
• each of said body members comprising a fiber of light transmissive material which serves as a light guiding path and transmits light therethrough necessary for activating a photocatalyst, each of said fibers having a plurality of protrusions distributed along the length thereof, to form between the fibers in the bundle a plurality of passages which enable a fluid to be passed therethrough while filtering any contaminants therefrom, and a layer of said photocatalyst formed on a surface of each of said fibers and said protrusions, wherein rays of said light which are introduced incident upon a longitudinal end surface of said fibers leak out into said layer of photocatalyst, while said rays of light propagate through said fibers, so as to directly irradiate said layer of photocatalyst.