Abstract
A perfect focusing mass spectrometer has been investigated and the tests were carried out with electrons in the energy range up to 1 KeV concerning both properties of the perfect velocity focusing and of the perfect direction focusing. A luminous intensity of more than 95 percents was obtained experimentally for s=1, where s is a field parameter connecting the electric and the magnetic fields. In addition, the resolving power of this spectrometer was experimentally studied and compared with theoretical results.