ANTIBACTERIAL TREATMENT METHOD FOR FIBER, METHOD FOR PRODUCING ANTIBACTERIAL FIBER AND ANTIBACTERIAL FIBERDisclosed are a method for the antimicrobial treatment of a fiber and a process for the production of an antimicrobial fiber, each of which is characterized by immersing the fiber in an aqueous solution containing a noble metal ion or a noble metal complex and irradiating the aqueous solution with γ-ray or electron beam. In the method for the antimicrobial treatment of a fiber and the process for the production of an antimicrobial fiber, the noble metal constituting the noble metal ion or the noble metal complex is at least one noble metal selected from the group consisting of gold, silver, platinum, palladium, ruthenium, rhodium, iridium and rhenium. Also disclosed is an antimicrobial fiber produced by the process.