PURPOSE: To regulate suitably the amount of dampening water on the surface of plate cylinder and at the same time to make the partial selection of the amount of dampening water possible, by a method wherein each specified amount of dampening water is atomized under the operation of plural number of ultrasonic vibrators and the atomized dampening water is directly fed from plural number of apertures having the width of a specific length to a rooler or the plate cylinder.

CONSTITUTION: When the voltage of a specific intensity is applied to ultrasonic vibrators 40aW40n, the fixed amount of dampening water in water vessel 34 are respectively atomized in cylindrical parts 24aW24n with the ultrasonic vibrators 40aW40n. Then, the atomized dampening water are conducted outward from aperture parts 30aW30n and adherred to the water averaging roller 46 arranged above a dampening equipment 20. Then, when this water averaging roller 46 is displaced in the direction of C arrow mark by rotation in a specific direction, the dampening water adhered thereto is transferred to a water moistening roller 48 and further, is transported from the water moistening roller 48 to a plate cylinder 44.