A new hyperboloid mass spectrometer with ion separation along one axis was examined. The electrode system consists of two electrodes, each of these has accurately machined hyperbolic internal surfaces, with a shielding electrode. An impulse signal is used, which provides phase ion injection into a field free volume of the analyser. An estimated trapping coefficient of analysed ions and a sorting rate predict high efficiency of the suggested separation method and its capabilities. The achieved mass resolution is about 103.