To provide a method for purifying a carboxymethylcellulose(CMC), capable of extremely reducing the content of a remaining organic solvent in the CMC, especially capable of reducing the content of methanol so as to be ≤500 ppm in the method for producing the CMC by a solvent method.

This method for purifying a crude CMC comprises a wetting step for bringing the crude CMC containing the remaining organic solvent into contact with water in an amount sufficient to wetting the film formed on the surface of the CMC, and a drying step for evaporating and removing the remaining organic solvent in combination with the water by drying the wetted crude CMC in the method for producing the CMC by treating a mercerized cellulose in the presence of the organic solvent by an etherizing agent. A steam is used as the water, and 100 pts.wt. of the crude CMC is brought into contact with 4-25 pts.wt. of the water in the wetting step. Further, the drying is carried out at 60-140°C in the drying step in the method for purifying the crude CMC. The crude CMC is powdery one obtained at the steps after a deliquoring step in the method for purifying the crude CMC.