  Experimental results and perspectives of different methods to measure the
absolute mass scale of neutrinos are briefly reviewed. The mass sensitivities
from cosmological observations, double beta decay searches and single beta
decay spectroscopy differ in sensitivity and model dependance. Next generation
experiments in the three fields reach the sensitivity for the lightest mass
eigenstate of $m_1<0.2eV$, which will finally answer the question if neutrino
mass eigenstates are degenerate. This sensitivity is also reached by the only
model-independent approach of single beta decay (KATRIN experiment). For higher
sensitivities on cost of model-dependance the neutrinoless double beta decay
search and cosmological observation have to be applied. Here, in the next
decade sensitivities are approached with the potential to test inverted
hierarchy models.
