A measuring probe for a measuring device for ascertaining and monitoring fill level of a medium in a container. The measuring probe includes: a probe holding element, which is mounted on the container; and a probe element, which is secured in an axial bore of the probe holding element by means of a releasable securement structure. A first cavity is provided in the axial bore of the probe holding element and a second cavity on the probe element, and a locking element is provided, which, in a final position of the mounting of the probe element in the probe holding element, protrudes into the first cavity and into the oppositely lying second cavity on the probe element and, thus, forms an axial locking.