A method is provided for purifying a resin for photolithography wherein, from an insufficiently purified resin (also referred to as “crude resin”), low molecular weight impurities such as an unreacted monomer and a polymerization initiator, which cause a development defect of a resist pattern or deterioration of the storage stability of the resin for photolithography can be removed more effectively. The method for purifying a resin for photolithography includes an operation (a) wherein a slurry in which a resin is dispersed in a solution containing a good solvent and a poor solvent is stirred, and then an operation (b) wherein, to said slurry, a poor solvent is added to lower the ratio of the good solvent to the poor solvent, and then, the resin is separated from the solution.