Abstract: The multipole element has an even number of pole pieces (PS, PS') which are rranged symmetrically with respect to the optical axis (OA) of an electron beam measuring device and are rigidly connected to a ring-shaped yoke (J) by bar-shaped mounting elements (PH, PH'). A beam tube (SR), which is made from an electrically insulating material and has vacuum-tight ducts to receive the mounting elements (PH, PH') which are rigidly connected to the pole pieces (PS, PS'), is arranged coaxially with respect to the optical axis (OA) inside the yoke (J) which serves to guide the magnetic flux. The coils (SP, SP') for magnetic excitation of the pole pieces (PS, PS') are arranged on the parts of the mounting elements (PH, PH') lying outside the beam tube (SR). In order to generate an electrical multipole field suitable potentials (U, U') are applied to the pole pieces (PS, PS').