To increase the concentration of a useful gas by remarkably shortening an ice making time by an ice making machine by sufficiently cooling gas dissolution water in advance, to suppress the increase of equipment cost, and to inexpensively make ice including useful gas of high concentration.

This method of making useful gas-containing ice comprises a gas dissolving portion 1 for producing ozone water by dissolving an ozone gas into material water, the ice making machine 51 for making ice by freezing the obtained ozone water, and a pre-cooling portion 2 disposed on the way of a supply passage for distributing the ozone water obtained in the gas dissolving portion 1 to the ice making machine. The pre-cooling portion is provided with a plurality of resistors disposed in the flow channel in a cylindrical casing 43, a jacket 44 disposed on the outer periphery of the casing for circulating a refrigerant body, and a static mixer 41 having a heat exchanging function to cool the ozone water while stirring the ozon water.