A polypeptide hydrogel of the present invention is a hydrogel of a polypeptide derived from spider silk proteins, and has a moisture content of 85.0 to 99.9 mass% based on 100 mass% of the polypeptide hydrogel. A method for producing the hydrogel includes: a solution production step in which a polypeptide derived from spider silk proteins is dissolved in at least one dissolving solvent selected from the group consisting of (A) dimethyl sulfoxide (B) dimethyl sulfoxide with an inorganic salt and (C) N, N-dimethylformamide with an inorganic salt, so as to obtain a solution of the polypeptide and a substitution step in which the solution produced in the solution production step is substituted with a water-soluble solvent. Thus, the present invention provides a polypeptide hydrogel having excellent water retentivity and a polypeptide hydrogel suitable for application to a living body.
