Rezumat
Influence of free, reflecting surfaces on the cavitation zone excited by parallel underwater discharges is described in the article. Interaction of afterdischarge cavitation pocket and streams with different surfaces is shown. The way of efficiency increasing is offered for electrodischarge cavitation treatment of small ob- jects. The change of stream's direction of motion in the cavitation zone, especially in vertical direction, is possible by positional relationship combining of reflecting surfaces in a reactor.