This invention provides a functional peptide fiber which comprises a plurality of peptide structure units each containing at least one peptide chain, wherein peptide chains contained in each adjacent peptide structure units do not form peptide bond but are structured into a fibrous form by taking a .beta.-sheet structure, and wherein at least one of the plurality of peptide structure units contains a peptide chain having a functional material connected thereto. Also disclosed are a method for producing the functional peptide fiber and a method for recovering peptide chains from the functional peptide fiber.