Disinfection device intended for installation into water dispenser having an accumulating reservoir (1) for drinking water filled from an external source of drinking water, including: a flow-through ozone-air mixture generator (4) provided with an air pump (6) for external air delivery via an air filter (10) to the ozone-air mixture generator (4), wherein an output of the ozone-air mixture generator is connected with a delivery pipeline (2) for delivery of ozone-air mixture or air inside the delivery pipeline (2) an electromechanical ultrasonic frequency irradiator (3) mounted on the delivery pipeline (2) to generate ultrasonic oscillations in the pipeline (2) walls and in water filling the pipeline (2) a program control unit (8) to control the operation of the ozone-air mixture generator (4), air pump (6) and electromechanical irradiator (3) for disinfection and cleaning of inner surfaces of the pipeline (2) and water therein. Method is also proposed for disinfection of water dispensers.
