To provide a carboxymethyl cellulose salt (CMC salt) that suppresses the reduction in its viscosity to the utmost and has an enhanced powder whiteness.

A method for producing the above CMC salt comprises a step (a) of producing an aqueous solution of the CMC salt by converting a cellulose to an alkali cellulose and etherifying the alkali cellulose, a step (b) of separating the CMC salt by neutralizing the aqueous solution of the CMC salt and a step (c) of bleaching the CMC salt with a bleaching agent, wherein the aqueous solution of the CMC salt after neutralized in the step (b) has a pH of 7.0-9.0; the weight ratio of a solvent to a CMC salt solid matter in the CMC salt separated from the aqueous solution of the CMC salt is 0.5-3.0; and in the step (c), a 1-5 wt% aqueous solution of hydrogen peroxide as a bleaching agent is added at 40-80°C in an amount of 2-10 pts.wt. based on 100 pts.wt. CMC salt.