An apparatus for sterilizing at least a segment of an inner wall and a segment of an outer wall of containers by accelerated charge carriers, includes at least one first external application device for sterilizing at least a segment of an outer wall of containers and an internal application device for sterilizing at least a segment of an inner wall of containers. The internal application device at least in portions is arranged to be introduced through an opening into the container in order to apply the emitted charge carriers to an inner wall of the container. The containers are transported along a transport path during their sterilization, wherein along a segment of the transport path of the containers between the first external application device and the internal application device is arranged a pitch change device to change a distance between two containers succeeding each other along the transport path.