PURPOSE: To clean the lower surface of a printing mask regularly and automatically by means of a wiper body thereby to make it possible to use said printing mask for long hours by a method wherein said band-like wiper body equipped with a solvent supplying unit is held by a winding roller, and said winding roller is allowed to slide while in press contact with the lower surface of said printing mask.

CONSTITUTION: A wiper body 16 having suitable tensile strength and water absorptivity is impregnated with an appropriate amount of a solvent 25 by a solvent supplying unit 14. The wiper body 16 is uniformly pressed between the lower surface of a printing mask 4 and a winding roller 15, so that a printing body 23 adhered to the lower surface of the printing mask 4 is rendered low in viscosity while the adhesiveness and delamination property of the printing body 23 to the wiper body 16 are enhanced by the solvent 25 impregnated in the wiper body 16. As a result, the printing body 23 is wiped. At this time, since the wiper body 16 slides while it is in press contact with the lower surface of the printing mask 4 via the winding roller, wiping of the printing body 23, namely, cleaning of the lower surface of the printing mask 4 can be regularly and automatically carried out with good efficiency.