A 10x reticle must meet quality criteria completely because one defect, if its size exceeds the resolution of the photorepeater lens, may degrade the performance of all the related IC chips, or even cause their complete failure. The mask surfaces, therefore, must be cleaned thoroughly. The usual method, air-cleaning with a hand-held pressure nozzle, does not remove all the small particles. Liquid cleaning is more effective, but is expensive and usually involves toxic materials. The results of dry cleaning have been improved substantially by a system in which suction is applied instead of blowing. The basic system consists of a hollow metal tube connected to a vacuum pump. A long slit in the tube is brought close to the contaminated surface, which is moved past it on a linear stage. Some particles are not relloved by the air flow alone; mechanical action applied by a slowly vibrating brush dramatically improves the particle removal rate. The cleaning system effectively removes particles of glass, plastic, dandruff, and unknown materials. A few remarks on adhesion forces are given in an appendix.