Abstract: An apparatus internally inspects a workpiece having a hollow cylindrical hole. The apparatus contains an ultrasound transducer configuration having a plurality of ultrasound transducer elements, which are arranged in at least one row, one next to the other, in an elastically deformable carrier which has the form of a segment of a hollow cylinder and has a plurality of sliding pimples which extend in the longitudinal direction of the carrier and project with a protrusion in the radial direction beyond the transmitting and/or receiving surfaces of the ultrasound transducer elements.