PROBLEM TO BE SOLVED: To provide a resin porous body with high thermal stability and high strength, and to provide a method for producing the same.SOLUTION: A resin porous body includes modified cellulose nanofibers in the resin, where a hydroxyl group of cellulose nanofiber is modified with a modification group that has a chemical structure which has two or more carbon atoms having fluorine atoms bonded thereto. A method for producing the resin porous body comprises: a preparing step of preparing a resin composition including the modified cellulose nanofibers, a resin, and a pore-forming agent a molding step of molding the resin composition and an elution step of eluting the pore-forming agent from the molded article obtained in the molding step.
