A piezoelectric transducer including a substrate, a piezoelectric layer and a stiffening structure is provided. The substrate has a chamber. The piezoelectric layer has a displacement zone, a plurality of sensing zones, a plurality of gaps, a plurality of top electrodes, and a plurality of bottom electrodes. The displacement zone is located over the chamber. The sensing zones are surroundingly connected to an outer edge of the displacement zone and are located over the chamber. The gaps are each formed between any adjacent two of the plurality of sensing zones, and each of the gaps communicates with the chamber. The top electrodes are each disposed on a top surface of each of the sensing zones. The bottom electrodes are each disposed on a bottom surface of each of the sensing zones. The stiffening structure is disposed on a bottom of the displacement zone.