Abstract: A piezoelectric/electrostrictive element having a piezoelectric body, a through-hole electrode, a first electrode, a second electrode, a third electrode. The piezoelectric body includes a through-hole in communication with a first main surface and a second main surface. The through-hole electrode is formed on an inner side surface of the through-hole. The first electrode is formed on the first main surface of the piezoelectric body, and connected to the through-hole electrode. The second electrode is formed on the second main surface of the piezoelectric body, and is connected to the through-hole electrode. The third electrode is formed on the second main surface of the piezoelectric body and isolated from the second electrode. A calculated average roughness in the inner side surface is larger than 0.11 microns and smaller than 16 microns. A maximum height roughness in the inner side surface is larger than 0.2 microns and smaller than 20 microns.

Abstract: A piezoelectric/electrostrictive element has a piezoelectric body, a through-hole electrode, a first electrode, a second electrode, a third electrode. The piezoelectric body includes a through-hole in communication with a first main surface and a second main surface. The through-hole electrode is formed on an inner side surface of the through-hole. The first electrode is formed on the first main surface of the piezoelectric body. The first electrode is connected to the through-hole electrode. The second electrode is formed on the second main surface of the piezoelectric body. The second electrode is connected to the through-hole electrode. The third electrode is formed on the second main surface of the piezoelectric body. The third electrode is isolated from the second electrode. A calculated average roughness in the inner side surface is larger than 0.11 microns and smaller than 16 microns. A maximum height roughness in the inner side surface is larger than 0.2 microns and smaller than 20 microns.