Direct neutrino mass experiments - present and future

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 in the early universe. The current tritium beta decay experiments at Mainz and Troitsk are reaching their sensitivity limit. The synchronous measurements at Mainz and Troitsk show that the Troitsk anomaly is an experimental artefact. The different options for a next generation direct neutrino mass experiment with sub-eV sensitivity axe discussed. The KATRIN experiment, which will investigate the tritium beta spectrum with a 1 eV resolution MAGE-Filter, is being prepared to reach a sub-eV sensitivity.