Multifunctional air filter and air-circulating clean unit with the same incorporated therein

A multifunctional air filter module with at least one replaceable and reusable fabric filter element for reducing both organic and inorganic contaminants, said module comprising:

• a filter case having an air introduction side opening and an air discharge side opening;
• a pleated fabric filter element selected from the group consisting of an activated carbon fiber having no further chemical contaminant absorptive substance attached thereto, a combination of said activated carbon fiber and a reinforcing fiber, and a combination of a fabric and activated carbon particles contained therein, positioned in said filter case in such a way that said pleated fabric filter element extends across an air flow directed from said air introduction side opening to said air discharge side opening, said pleated fabric filter element having a periphery that is fixed to said case without a clearance therebetween;
• and
• at least one replaceable fabric filter element formed of a fabric selected from the group consisting of a fabric containing an activated carbon having a strong base attached thereto, a fabric containing an activated carbon having KMnO.sub.4 attached thereto, a fabric containing an activated carbon having ZnCl.sub.2 attached thereto, a cation exchange fiber fabric, and an anion exchange fiber fabric, said replaceable fabric filter element being simply placed in air introduction side grooves formed by said pleated fabric filter element and having a periphery not attached to said case.