For example in the ultrasonic oscillator of this invention and the ultrasonic diagnostic device which uses this, the plural piezo-electric devices are provided for 2 dimensional array condition, organic piezo-electric device array 30 and the integrated circuit 40 in reception ultrasonic traveling direction is arranged in this order, in wiring layer 42 of the integrated circuit 40, adjusting to the electrode pitch in the plural piezo-electric devices, in order to cover the individual electrode, sealed electrode 47 is respectively formed, each sealed electrode 47 the reception signal from the piezo-electric device which corresponds to particular sealed electrode 47 through the circuit 45, is given low with impedance.本発明の超音波振動子およびこれを用いた超音波診断装置では、複数の圧電素子を2次元アレイ状に備える例えば有機圧電素子アレイ30と集積回路40とが受信超音波の進行方向にこの順で配置され、集積回路40の配線層42には、複数の圧電素子における電極ピッチに合わせて、個々の電極を覆うようにシールド電極47がそれぞれ形成され、各シールド電極47は、当該シールド電極47に対応する圧電素子からの受信信号が回路45を介して低インピーダンスで与えられる。
