To provide fibers effectively exhibiting a high insecticidal action and an aromatherapeutic action corresponding to a forest bathing at a low production cost, and to provide the product of the fibers.

Natural fibers or a fiber product obtained by at least partially weaving or knitting the natural fibers are immersed in an essential oil L containing a cedar aromatic ingredient and obtained by purifying cedar. Synthetic fibers 10 or a woven or knitted fiber product at least partially containing the synthetic fibers 10 are kneaded with the essential oil L.