The preferred embodiment of the invention provides a gas generator comprising an ion membrane electrolytic cell and an atomized/volatile gas mixing tank. The ion membrane electrolytic cell comprises an ion exchange membrane, a cathode chamber and an anode chamber. An anode electrode is set in the anode chamber, and a cathode electrode is set in the cathode chamber. The ion exchange membrane is set between the anode chamber and the anode chamber. When water is electrolyzed by the ion membrane electrolytic cell, oxygen is generated by the anode electrode and hydrogen is generated by the cathode electrode. The atomized/volatile gas mixing tank coupled to the ion membrane electrolytic cell accepts the hydrogen generated from the ion membrane electrolytic cell and generates an atomized gas to mix with the hydrogen for generating a healthy gas.