of air bubbles could become lessened with the passage of time because air dissolving in the water is used up however as mentioned above part of the air fed from the bubble supplying room 33 dissolves in the water from time to time so that air bubbles are constantly formed and never disappear therefore stains or alien matters are completely removed after washing the ultrasonic generator 2 and the air pump 3 are switched off to stop spent water in the tub 1 and the bubble supplying room 33 is exhausted from the pipe 41 when the valve 4 is switched to the pipe if the next washing has to be made without exhausting spent water then the valve 4 is switched to the pump 43 and the pump 43 is caused to work spent water is filtered by the filter 42 and fed back into the tub 1 by way of the valve 44 the filter 42 being replaceable spent water can be used again and again therefore a considerable amount of water can be saved economically similar to the first embodiment the second embodiment and a variation thereof will be explained with referrence to fig2 and 3 in which the same elements and elements whose action is practically the same as those in the first embodiment are designated by the same numeral used in fig1 in fig2 a rotary drum 52 having many holes 51 on the circumference thereof is supported horizontally almost in the center of a tub 1 a long fabric or a bundle of.