An apparatus for generating pressure pulse/shock waves (PP/SWs) is disclosed which comprises a pressure pulse/shock wave (PP/SW) source, a housing enclosing said PP/SW source, and an exit window from which wave fronts of waves generated by said PP/SW source emanate. The wave fronts have plane, nearly plane, convergent off target or divergent characteristics. In one embodiment, an extracorporeal shock wave system provides a planar wave for the treatment of tissue. A parabolic reflector is provided in order to propagate the planar wave through a membrane and to the tissue of a human subject. A piezoelectric, electrohydraulic or electromagnetic source may be used to develop the wave.