Abstract: An apparatus is described for locating objects within the body, and particularly concretions situated in body cavities, in three dimensions and for destroying them. The point of departure for this is an electro-acoustic treatment transducer for generating shock waves to be emitted to focus on the object concerned and a B-scanner connected to the treatment transducer to act as a locating transducer for locating the object, the locating transducer being adjustable relative to the treatment transducer co-focally therewith. The design proposed envisages the locating transducer being integrated into the treatment transducer so that the sound fields of both transducers travel the same distances through the same media and it is thus the correct position of the focus relative to the concretion seen in the image which is in fact shown.