A device for filling a container with a sterilized filling product, preferably for filling a beverage container with a sterilized beverage in a beverage bottling installation, comprising a sterilization device for sterilizing the filling product, a sterile tank for buffered receiving of the filling product sterilized in the sterilization device, and a filling device which has a filling valve for the filling of the container to be filled, wherein the filling valve is a proportional valve for controlling and/or regulating the filling-product flow of the filling product into the container to be filled, and the proportional valve is connected in a buffer-free manner to the sterile tank.