In order to examine the characteristics of a concentrator using ultrasonic atomization, an ethanol aqueous solution was used and ultrasonic atomization concentration was performed under various conditions such as different ultrasonic conditions, liquid mixing methods and vessel diameters. The now rate of accompanied liquid had a maximum against the initial liquid height, and the optimum initial liquid height decreased with increasing ultrasonic frequency. The flow rate of accompanied alcohol increased with increasing net electric power to a transducer, but was hardly affected by the ultrasonic frequency. In the case of mechanical agitation, as the revolution speed of a stirrer was faster, the flow rate of accompanied liquid increased but the alcohol content in accompanied liquid decreased. As a result, the revolution speed had no significant influence on the now rate of accompanied alcohol. When the gas was sparged into liquid for liquid mixing, with increasing gas velocity, both the flow rate and the alcohol content of accompanied liquid became higher with increasing gas velocity, and the flow rate of accompanied alcohol increased. From these results, the liquid mixing by the sparging gas was found to be effective for the enhancement in performance of ultrasonic concentration. At the relatively high net electric power to an ultrasonic transducer, the now rate of accompanied liquid increased with increasing vessel diameter, but the alcohol content in accompanied liquid was hardly affected by the vessel diameter.