Abstract: The device for treatment of liquids by the help of generation of an electrically powered discharge of low-temperature plasma in liquid environment where is, when the liquid flows, possible to achieve generation of cavitation or super-cavitation which consists of mutually in series connected a pressure regulator and a cavitation tube which is formed by two mutually connected inlet chamber, confusor, working chamber, diffusor and a discharge chamber, where the essence of the invention is that there is in the inlet chamber in its lengthwise axis in direction of liquid flow placed a powered electrode which by its free end reaches into the working chamber and to it is electrically conductive connected a high voltage source whereas the powered electrode is electrically insulated from the body of the cavitation tube and also is in the discharge chamber placed a grounding electrode which is in electric contact with the liquid.