A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at √s ≃ ℳz with the ALEPH detector. Two separate limits are derived by fitting the distribution of visible energy vs invariant mass in τ- → 2π-π+vτ and τ- → 3π-2π+(π0)vτ decays. The two results are combined to obtain a 95% confidence level upper limit of 18.2MeV/c2 on the mass of the tau neutrino. Neutrinos play an important role in particle physics, astrophysics and cosmology. They are a potential window towards physics beyond the Standard Model, carriers of radiated energy in star evolution, candidates for dark matter and ingredients in models of evolution of the universe. Massive neutrinos can arise from many different mechanisms  but they are generally present in all extensions of the Standard Model. Among the possible frameworks.