The Faraday cup is used to measure the current of an ion or electron beam and follows a very simple principle. The charged particles hits an electrically insulated metal body, the charge is conducted to ground via an ampere meter, and the beam current can thus be measured. In detail, however, some side effects have to be taken into account. In the case of high-intensity beams, efficient cooling must prevent the destruction of the cup. High-energy beams have a large penetration depth into the material, which must be taken into account when designing the material thickness. An aperture system uses a high voltage to push back charged secondary particles that falsify the measurement result. Pair production has been taken into account with electrons. NTG has a special understanding of the design taking all these effects into account and offers customised solutions for the most diverse applications like with all of our beam diagnostic tools.