Abstract: A method for removing substances adhering to a surface such as a wall of buildings in which a nozzle head having a plurality of nozzles is rotated eccentrically and moved sidewardly when used. The diameter of each of the nozzles is selected so as to be within a range of 0.05 to 0.5 mm, the pressure to be supplied to the nozzles is 800 kg/cm.sup.2 or more, the total amount of water jetted from each of the nozzles is 12 l/min or less and the number of revolutions of the nozzle head is 800 to 4000 rpm.