A device for sterilizing containers may include a treatment head having an outlet window for the passing of charge carriers therethrough, a charge carrier generation source for generating charge carriers, an acceleration device disposed above the outlet window, and a cooling device for cooling the outlet window. The acceleration device accelerates the charge carriers in the direction of the outlet window. The cooling device includes a feed opening for a gaseous medium. The feed opening is disposed beneath the outlet window and directs the gaseous medium at least partially from below to the outlet window.