PROBLEM TO BE SOLVED: To provide a technique for safely obtaining a high density metal ion water.SOLUTION: Provided is a method for preparing the high density metal ion containing water, in which the following materials (a), (b), and (c) are mixed up under pH conditions higher than pH 5: (a) a burned product of a mixture of (i) a metal-support inorganic compound supporting one or more chosen from a group of silver, gold, copper, and zinc, (ii) a clay material, (iii) titanium dioxide, and (iv) a fine combustible material (b) clay material and (c) water.
