Abstract: The apparatus comprises two containers, which are adapted to be connected to a vacuum pump. The upper container contains a rotationally symmetrical guiding body. A distributing space is defined by the shell of the upper container and the closed peripheral surface of the guiding body and extends from the cover of the upper container to pipe lengths, which terminate at their lower end over cups arranged in the lower container. As a result, the apparatus permits an economical making of molds in series and meets the requirements arising in practice regarding the batchwise processing of batches in quantities which vary within an extremely wide range.