  It is described how one comes to the Wigner-Dyson random matrix theory (RMT)
starting from a model of a disordered metal. The lectures start with a
historical introduction where basic ideas of the RMT and theory of disordered
metals are reviewed. This part is followed by an introduction into
supermathematics (mathematics operating with both commuting and anticommuting
variables). The main ideas of the supersymmetry method are given and basic
formulae are derived. As an example, level-level correlations and fluctuations
of amplitudes of wave functions are discussed. It is shown how one can both
obtain known formulae of the RMT and go beyond. In the last part some recent
progress in the further development of the method and possible perspectives are
discussed.
