The present invention addresses the problem of providing: a non-fluid functional hydrogel which is formed from keratin
and a method for producing the functional hydrogel. The problem can be solved by a method for producing a functional hydrogel, which comprises the steps described below, and a functional hydrogel which is produced by the production method. (1) A step wherein a reducing agent for converting a disulfide bond to a thiol group is added to a keratin-containing material, so that keratin is extracted. (2) A step wherein a protein stabilizer for preventing a thiol group from re-forming a disulfide bond is added to the keratin-containing material. (3) A step wherein the keratin is purified by removing the protein stabilizer, thereby obtaining a keratin solution. (4) A step wherein a functional hydrogel is produced by concentrating the keratin solution.