  One of the most important tasks in neutrino physics is to determine the
neutrino mass scale to distinguish between hierarchical and degenerate neutrino
mass models and to clarify the role of neutrinos as dark matter particles in
the universe. The current tritium beta decay experiments at Mainz and Troitsk
are reaching their sensitivity limit. The different options for a next
generation direct neutrino mass experiment with sub-eV sensitivity are
discussed. The KATRIN experiment, which will investigate the tritium beta
spectrum with an unprecedented precision, is being prepared to reach a
sensitivity of 0.2 eV.
