A safety closure for steam-pressurized containers of household appliances, such as steam irons, steam cleaners and the like. The safety closure is provided with an inner part that can be screwed onto the filling hole of the container, and with an outer part in the shape of a grip cap. A coupling element is provided between the inner part and the outer part and can be axially displaced against the effect of a spring by a drive controlled by the internal container pressure in such a manner that the outer part and the inner part are interconnected in a rotationally fixed manner when the container is not pressurized The connection being neutralized when the container is pressurized. The aim of the invention is to provide a safety closure whose components that are exposed to the pressure are more solid and therefore function more reliably and whose drive at the same time serves as a protection from an inadmissibly high excess pressure. For this purpose, the drive for the coupling element is configured by a valve support which is axially mobile inside the inner part and which can be placed on the coupling element against the axial effect of a spring.