To provide a miniaturized hydrogen-oxygen gaseous mixture generator where the strength of electrode plates is improved to prevent electrical troubles, and further, the uniformization of the concentration in an electrolytic solution and cooling efficiency are improved.

An upper electrode 8 in which a plurality of cylindrical electrode plates 11 are concentrically arranged with intervals is mounted on a lower electrode 9 in which a plurality of cylindrical electrode plates 14 are cocentrically arranged with intervals in such a manner that the upper and lower cylindrical electrode plates 11 and 14 are confronted with gaps, so as to be stored inside cylindrical casting 16, thus an electrolytic cell 1 is formed. The electrolytic cell 1 is stored inside a box-shaped body case 5, and further, a gas exhaust port 29 formed on the upper part of the electrolytic cell 1 is connected with a coil-shaped gas cooling tube 3. One wall face of the body case 5 is fitted with a cooling fan 6, so as to be confronted with the gas cooling tube 3. Further, the other wall face of the body case 5 is provided with an exhaust port 7.