PROBLEM TO BE SOLVED: To provide a method of activating cells by ingesting magnesium chloride and of making maximum use of magnesium chloride maintaining a constant composition to cells of a living body in comparison with the conventional method, in which the manner of using magnesium chloride to discharge dead cells to outside of the body immediately for prevention of illness still remain using only the magnesium chloride maintaining a constant composition to cells of a living body.SOLUTION: The method of activating cells by ingesting magnesium chloride according to the present invention comprises taking in fresh milk and magnesium chloride at the same time to secure the balance of bloodstream while securing bowel movement and urination. The method also determines cells in more detail and enables maximum use of magnesium chloride maintaining a constant composition to cells of a living body, while achieving prevention of illness and canceration.