PROBLEM TO BE SOLVED: To allow hydrogen gas to dissolve in liquid and maintain dissolved degree of hydrogen gas in the liquid at high level.SOLUTION: A sealed bag 1 which is put into liquid and allows hydrogen gas to dissolve in the liquid consists of a hydrogen permeable film capable of letting hydrogen gas, which is filled and sealed inside the bag, to permeate to the outside. By submerging the sealed bag 1 in the liquid, hydrogen gas permeated from the hydrogen permeable film dissolves into the liquid. Further, since hydrogen gas continuously gradually permeates from the hydrogen permeable film, dissolved degree of hydrogen in the liquid is maintained at high level.SELECTED DRAWING: Figure 3
