A US element 20 includes a silicon substrate 11, wherein a lower electrode layer 12 that has a plurality of lower electrode sections 12A, and a plurality of lower wiring sections 12B, and is connected to a lower electrode terminal 52 to which a drive signal and a bias signal are applied, a lower insulating layer 13, an upper insulating layer 15 in which a plurality of cavities 14 are formed, an upper electrode layer 16 that has a plurality of upper electrode sections 16A and a plurality of upper wiring sections 16B, and is connected to an upper electrode terminal 51 at a ground potential for detecting a capacitance signal, and a protection layer 17 are sequentially stacked on the silicon substrate 11, and the US element 20 further includes a shield electrode section 71 that is formed at least at an upper side of the lower wiring sections 12B, and is connected to a shield electrode terminal 53 at a ground potential.
