An ultrasonic flow meter comprising two piezoelectric ultrasonic transducers each comprising a first and a second electrode; an ultrasonic flow meter housing, at least a part of which forms a support substrate for supporting the two piezoelectric ultrasonic transducers on an electrically conductive layer of the support substrate; an adhesive applied between the electrically conductive layer and the first electrode; wherein at least the first electrode of each piezoelectric ultrasonic transducer has a roughened surface, and wherein electrical connection between the electrically conductive layer and the first electrode is formed by said roughening.