Search for the kinematical mass of neutrino in the beta-decay of tritium. Perspectives of further refinment of the experiments.

Present results of the search for neutrino mass in the beta spectrum of tritium on the "Troitsk nu-mass" setup are discussed as well as comparison with other data. Perspectives to achieve sub-eV level of accuracy for neutrino mass and proposal for new experiments will be reviewed. Anomalous structures near to the end point of the tritium spectrum, observed in the measurements are discussed.