In the present study the preliminary results of process investigations, being part of the research programme which has been carried out at the Department of Process Equipment, Technical University of Lodz, have been presented. The investigations are aimed at the process examinations of a new double- frequency screen in respect of its usefulness for screening of finely grained loose materials. The main objective of the present study is to demonstrate the results of the process investigations of this screen for various drive configurations in the form of the graphical efficiency – and capacity dependencies.