A device for anti-bacterial treatment in particular decontamination and/or sterilisation of water and for killing micro-organisms in water, with a container designed to hold a water quantity intended to be treated and an electrode arrangement which is designed to act on the water quantity in the container and which can be connected and operated with an electrical signal generating device provided outside the container, where the electrical signal generating device can be operated low voltage and is intended to generate an electrical alternating signal between electrodes of the electrode arrangement with a maximum amplitude