The present invention provides a multi-functional nonwoven fabric for filter that has excellent properties to adsorb various toxic/harmful substances such as odorous substances, VOCs, allergens, and pathogenic viruses, has antibacterial/antimold properties, and suppresses pressure loss to a minimal level, and the present invention also provides a method that can produce such a nonwoven fabric in a simple manner. Due to the simple steps of immersing the nonwoven fabric in an aqueous polypeptide solution and further treating it with a metal salt, it is possible to obtain a nonwoven fabric for filter having excellent adsorption properties in which the fiber surface of the nonwoven fabric is coated with insolubilized polypeptide that has been crosslinked with a metal. Also, a method that can produce such a filter in a simple manner was found.
