Sterilization by heat can be carried out at a low cost, and there are many natural water products that are sterilized by heating. However, heat treatment causes partial loss of the minerals during the sterilization process. Non-heated treatment sterilizes the product without heating. Although it takes higher cost and labor, the process does not cause mineral loss. By doing so, the mineral contents of the natural can be maintained as it is. This is a special treatment that can only be used by manufacturers authorized by the Ministry of Agriculture, Forestry and Fisheries or the Ministry of Health, Labor and Welfare.