This paper presents the development of an acoustic energy harvester using the sonic crystal and the piezoelectric material. A point defect is created by removing a rod from a perfect sonic crystal. The point defect in the sonic crystal acts as a resonant cavity, and the acoustic waves at the resonant frequency of the cavity can be localized in the cavity. The power generation from acoustic energy is based on the effect of the wave localization in the cavity of the sonic crystal and the direct piezoelectric effect of the piezoelectric material.