To provide a method for producing ether carboxylic acids, capable of preventing a yield of the product from being reduced and capable of inhibiting a reaction time therefor from being prolonged, when the ether carboxylic acids are produced by repeatedly using a rare earth-based catalyst, and further capable of shortening a time required for conducting a production process by accelerating dissolution of the recovered rare earth-based catalyst.

This method for producing the ether carboxylic acids comprises repeatedly using the rare earth-based catalyst, wherein the method includes a catalyst-recovering process for recovering the rare earth-based catalyst in a carbonate salt form from a reaction solution containing the rare earth-based catalyst and the production process for producing the ether carboxylic acids by dissolving the rare earth-based catalyst in the carbonate salt form in the reaction solution, and further the production process includes a procedure for removing a part or the whole of carbon dioxide emitted by proceeding of the dissolution of the rare earth-based catalyst in the carbonate salt form.