To provide an industrially advantageous method for purification of a styrene-fumarate copolymer capable of collecting a highly purified styrene-fumarate copolymer from a reaction mixture obtained by a direct esterification reaction of a styrene-fumaric acid copolymer with an alcohol.

The method for purification of the styrene-fumarate copolymer includes: a step of contacting a reaction mixture 1, which contains the styrene-fumarate copolymer obtained by the direct esterification reaction of the styrene-fumaric acid copolymer with the alcohol using an acid catalyst, with methanol 2 or ethanol; and a step of extracting a component except the styrene-fumarate copolymer from the reaction mixture 1.