The neutrinoless double-β decay is a hypothetical nuclear
transition predicted by most of the theories that explain the origin
of neutrino masses or the dominance of matter over antimatter in
our Universe. Its discovery would unambiguously prove that the
lepton number is not conserved and neutrinos are their own
antiparticles. The experimental search for the neutrinoless
double-β decay is a very active and rapidly growing field, with
several experiments running and many others under preparation.
The talk will cover the theoretical and experimental aspects
connected to the neutrinoless double-β decay, with focus on the
experimental program based on Ge-76.