34 p1 34 and direction 2 converting valve 228 connected to second check valve 224 is positioned at 34 p3 34 accordingly when power is transmitted to vibrator 207 through reciprocation shaft 211 according to the driving of a driving portion 210 washing by non linear resonance is performed in washing tub 201 meanwhile air in cylinder 212 repeats the intaking and exhausting processes according to the up and down movements of piston 213 installed on reciprocation shaft 211 when piston 213 rises air as much as the stroke volume of piston 213 is intaken through first air inhaling blocking valve 221 and first check valve 223 since the lower portion of cylinder 212 bears lower pressure on the contrary the air in the upper portion of cylinder 212 becomes contracted by that much however since only second air inhaling blocking valve 222 is open the air is exhausted through the second air inhaling blocking valve 222 when piston 213 falls air is intaken into cylinder 212 through second air inhaling blocking valve 222 and third check valve 226 and exhausted through first air inhaling blocking valve 221 since direction 2 converting valve 228 connected to second check valve 224 is positioned at 34 p3 34 and air sequentially passing through second check valve 224 34 b 34 and 34 t 34 are blocked by second air supplying valve 220 there will be no flow also after washing is completed in dehydration step 1 draining valve 216 and second air supplying valve 220 are open and first and second air inhaling blocking valves 221 and 222 water supplying valve 214 and.