Patent ID: 8502434

Claim:
A multi-layer piezoelectric element, comprising: a multi-layer structure comprising a plurality of internal electrode layers and a plurality of piezoelectric material layers, the plurality of piezoelectric material layers being stacked with each one of the plurality of internal electrode layers intervened between each two of the plurality of piezoelectric material layers, wherein a cross-sectional area of a cross section of the multi-layer structure parallel to the plurality of internal electrode layers is smaller in both end portions in a stacked direction than in a middle portion in the stacked direction, wherein the multi-layer structure comprises a sectional area reducing portion where the cross-sectional area becomes smaller toward both ends in the stacked direction, an opposing portion where the plurality of internal electrode layers oppose each other, and non-opposing portions positioned on sides of both ends of the opposing portion in the stacked direction, and wherein the sectional area reducing portion is formed so as to extend across the opposing portion and the non-opposing portions.