Abstract: The invention provides a device for the ultrasonic inspection of a multilayer metal workpiece consisting of at least one parent metal layer and a clad metal layer, and having an outer surface, at least one boundary surface, and an inner surface, the device comprising a housing accommodating at least three spaced-apart, ultrasonic transducing means capable of receiving electrical input signals, initiating transmission of ultrasonic waves to the workpiece, and receiving reflected ultrasonic waves to be transduced into electrical output signals, the transducing means being constituted by an acoustic prism having a first face for at least indirectly contacting a workpiece, a second face extending in a plane forming an angle .alpha. with the plane of the outer surface of the workpiece, and a piezocrystal attached to the second face, wherein the distance L.sub.