A method and device for reusing materials and/or products by pulsed power according to which a series of electrical discharges are generated between at least two electrodes in a reactor containing an ambient liquid as well as the materials and/or products to be reused. The energy of the electric discharges, the voltage between the electrodes, the switching time and the frequency of the discharges are selected such that said discharges generate electric arcs that pass through the materials and/or products to be reused, and mechanical shock waves that propagate across the materials and/or products to be treated in the reactor. The result is fragmentation, pulverisation, dispersion and separation of the elements that make up the materials and/or products to be reused.