The invention relates to a device for sterilising water, comprising a UV lamp (50), at least one vessel (30) through which water flows, an inlet (32) and an outlet (34), a reaction chamber (35) being arranged in said vessel. The outlet (34) of the container forms a free down spout. The UV lamp (50) and the vessel (34) are arranged in a cartridge (10), the cartridge comprising at least fixing means (20) for detachable fixing to a connection device (1), and connection means (22,24) for supplying the current and water from a connection device (1).
