An ultrasonic transducer comprises an elongate horn, a counterpiece, two piezoelectric drives and a screw. The counterpiece is fastened to the horn by means of the screw and thus clamps the piezoelectric drives, which are arranged on either side of a longitudinal axis of the ultrasonic transducer, between the horn and the counterpiece. The ultrasonic transducer is designed in such a way that the tip of a capillary which is clamped in the horn can oscillate in two different directions.