Abstract: An energy-trapping piezoelectric vibration device generates a thickness shear mode and includes an elongated piezoelectric element having first and second longitudinally opposed ends, top and bottom surfaces provided between the first and second ends such that the top and bottom surfaces oppose each other, and beveled surfaces disposed at a vicinity of the first and second ends such that the thickness of the piezoelectric element gradually decreases towards the first and second ends, respectively. First and second vibration electrodes are disposed on the top surface and the bottom surface of the piezoelectric element, respectively. The first and second vibration electrodes are located at an approximate middle portion of the piezoelectric element so as to oppose each other with the piezoelectric element disposed therebetween, to define opposing portions which constitute a vibrator.