PIEZOELECTRIC ELEMENT

PROBLEM TO BE SOLVED: To provide a piezoelectric element which disperses stress acting on a root of a stress relaxation layer and prevents destruction.SOLUTION: A laminate type piezoelectric element 100 is formed into a rectangular shape and expands and contracts when a voltage is applied. The laminate type piezoelectric element 100 includes: an element body formed by alternately laminating piezoelectric layers 110 and internal electrodes 120; and a stress relaxation layer 140 provided so as to contact with an outer periphery of the element body and formed along a lamination surface. The stress relaxation layer 140 has a rectangular inner periphery 141 with rounded corners. The structure avoids stress concentration to a root of the stress relaxation layer 140 and prevents the destruction. That is, even if the stress relaxation layer 140 is opened in conjunction with the displacement of the piezoelectric element 100, the stress acting on the root of the stress relaxation layer 140 is dispersed and the destruction of the piezoelectric element 100 is prevented.