PURPOSE: To produce effective liq. for longevity by bringing the hot gas spouting spontaneously from the strata in hot spring areas into contact with stones and rocks and corrosion resistant metallic materials through a collecting pipe to cool and lquefy said gas and refining the liquefied liq.

CONSTITUTION: The hot gas spouting spontaneously from the strata in hot spring areas is passed through the inside of a collecting pipe 1, and is injected concentrically through the opening in the upper part so as to collide against the outside circumferential surfaces of, for example, stones and rocks 12 in the part right above said opening. The hot gas cools and lquefies. The liq. is cotained in a liq. receiver 5, and is stored through liq. conduits 6 into liq. storage tanks 6. The liquid stored in the tank is discharged through suction pipes 8 and is refined by distillation or the like.