Disclosed is a SAW- or PSAW-type acoustic wave transducer in which a dielectric (DK) is applied to the substrate in such a way that the gap (GP) between the ends of the electrode fingers and the opposite bus electrode is entirely filled with the dielectric (DK), but the active region of the transducer, i.e. the transverse overlapping area (UB) between the electrode fingers, is not covered by the dielectric (DK).