PROBLEM TO BE SOLVED: To provide an ultrasonic element 20 in which characteristics are stabilized.SOLUTION: An ultrasonic element 20 comprises: a silicon substrate 11 a lower electrode layer 12 having a plurality of lower electrode parts 12A and a plurality of lower wiring parts 12B and 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 on which a plurality of cavities 14 which are smaller than the lower electrode parts 12A are formed an upper electrode layer 16 which has a plurality of upper wiring parts 16B and a plurality of upper electrode parts 16A disposed facing the lower electrode parts 12A via the cavities 14, respectively, and smaller than the lower electrode parts 12A but larger than the cavities 14, and which is connected to an upper electrode terminal 51 of ground potential for detecting a capacity signal and a protection layer 17.COPYRIGHT: (C)2013,JPO&INPIT【課題】特性が安定し超音波エレメント20を提供する。【解決手段】超音波エレメント20は、シリコン基板11と、複数の下部電極部12Aと、複数の下部配線部12Bと、を有し駆動信号およびバイアス信号が印加される下部電極端子52と接続された下部電極層12と、下部絶縁層13と、前記下部電極部12Aより小さい複数のキャビティ14が形成された上部絶縁層15と、それぞれの前記キャビティ14を介して、それぞれの前記下部電極部12Aと対向配置している、前記下部電極部12Aより小さく前記キャビティ14より大きい複数の上部電極部16Aと、複数の上部配線部16Bと、を有し、容量信号を検出するグランド電位の上部電極端子51と接続された上部電極層16と、保護層17と、を具備する。【選択図】図6
