An electrochemically activated water-based solution obtainable by electrolysis of brine-containing water in an electrolysis module (2) comprising a multitude of electrolysis cells (40) should have a particularly high bactericidal or antibacterial effect combined with particularly long storage stability, i.e. more particularly even after comparatively long storage for, for example, more than two years. According to the invention, such a solution is obtainable by electrolysis of brine-containing water in an electrolysis module comprising a multitude of electrolysis cells (40), in which each electrolysis cell (40) comprises a first electrode space assigned to a first electrical polarity and a second electrode space which is separated therefrom by a membrane (46) and to which a second electrical polarity has been assigned, wherein the electrolyte is supplied to the first electrode spaces (40) of the electrolysis cells serially in the manner of a series circuit.
