A method for blow molding and filling sterile containers of preforms in a container treatment device containing a blow module, in which the preforms are transferred from a heating device to the blow module via transport devices, and the containers are transported to a filling machine and filled, where a sterilization treatment is performed each at the preforms and the containers, a main sterilization treatment is performed at the preforms between the heating device and the blow module, and only a subsequent sterilization treatment is performed at the containers on the transport path to the filling machine. Further, a device having a main sterilization module between the heating device and the blow module, and a subsequent sterilization module between the blow module and the filling machine.