It is generally difficult to clean paintings on a substrate such as paper or silk without damaging the substrate. The author first examined a suction table consisting of a glass-bead filter on which a piece of filter paper impregnated with chloramine-T as an indicator was placed. Then air was sucked through the paper and on the filter a few drops of water were added for five to 10 seconds. This test cleaning process decreased the quantity of chlorine contained in the paper by a factor of a hundred, the result being nearly equal to that obtained by immersing the paper in water for about 20 minutes. The effect of ultrasonic wave combined with the suction table was also examined. Since the efficiency of the separation of a contaminant from the substrate depends on their difference in density, malachite and azurite were found to be removed more easily from the filter paper than carbon. Since silk used commonly as the substrate for Japanese paintings allows water and air to pass through readily, silk can be successfully cleaned by using a suction-table combined with an ultrasonic transmitter. -- AATA