To allow a functional air filter to be hygienic, high in safety and deodorizing property by controlling propagation of a mold and various germs in a good productivity by a method wherein the functional air filter is composed of a knitted textile fabric using a fibrous material spun from a composition wherein a functional ceramic having an antimicrobial property and a deodorizing property is blended in a thermoplastic resin.

As a fibrous material, thermoplastic resins of polyolefin series, polyester series, and or the like are used. For a functional ceramic, silica, alumina, or the like are used as a base burnt product, and metals and metallic salts of silver, zinc, or the like are supported by or blended in these bases, and an antimicrobial operation and a deodorant effect are provided. Though an ordinary monofilament or the like can also be used as the fibrous material to be spun from the thermoplastic resin and the functional ceramic, a honeycomb woven structure is preferable from points of elasticity, flexibility, a ventilating property, a dust collecting property, and a dimensional stability while it is a composite monofilament of a core-sheath type wherein flexibility is maintained and spinning can be highly intensively executed even though a filler is blended. Thereby, an antimicrobial property and a deodorant effect can be expected, and it can be efficiently stably manufactured.