Abstract: The described method is for the preparation of a carbonate spring by supplying carbon dioxide to a carbon dioxide dissolver and dissolving the carbon dioxide in raw water and includes of measuring the pH of the formed carbonate spring, calculating the carbon dioxide concentration data of the formed carbonate spring from the measured pH value and the alkalinity of the raw water, and controlling the feed rate of the carbon dioxide supplied to the carbon dioxide dissolver so as to make the carbon dioxide concentration data equal to a preset target carbon dioxide concentration value. According to this method, a carbonate spring having a desired concentration can be easily prepared by using an inexpensive pH measuring device.