The paper presents the construction of a mass analyzer for the analysis of hydrogen-helium mixtures based on a magnetic prism using a three-stage circuit that includes two cylindrical capacitors. The choice of an ion-optical scheme that provides a high resolution of 3300, which is necessary for the separation of all nuclides formed during the analysis of hydrogen-helium mixtures, is justified. It is shown that the innovative «MS-Platform» technology makes it possible to ensure high assembly accuracy of the elements of the prism mass analyzer ion-optical circuit, which is necessary to realize all the advantages of a prism mass spectrometer compared to sector ones.