Fibers are immersed in an aqueous dispersion of superfine zeolite particles (average diameter 0.01-1.5 μm) and used as antibacterial or adsorbent fibers. Cotton, polyester, or acrylic fibers treated with cationic surfactants were dipped into an aqueous dispersion of zeolite Y (average diameter 0.657 μm) to absorb 26.6, 14.8, and 22.7 mg of zeolite Y/10 g of fiber, respectively, with good washfastness. Zeolite particles containing Ag, Zn, or Cu ions inhibited the growth of Staphylococcus aureus FDA 209p, and fibers containing the Ag ion-containing zeolite Y showed good antibacterial effects with washfastness. The fibers containing zeolite Y showed good absorption of CO 2 and H 2 O.