While controlling the increase of the number of focusing data, although it squeezes beam width, it actualizes, because more ideal ultrasonic diagnostic device, the plural vibrating elements which convert the ultra wave and the electric information which the expedient have with the expedient 20 which, indicates 18 which reconstructs the ultrasonic image in the ultrasonic probe on the basis of the signal which is output from the reception expedient 16 which processes the reception signal which is output from the transmission expedient 12 which supplies the drive signal 10 which sends and receives the ultra wave with the suffering inspection bodies and ultrasonic probe 10 and ultrasonic probe 10 and reception expedient 16 and the ultrasonic image form ultrasonic probe 10 mutuallyInside, the element selective expedient 22 which selects the plural drive vibrating elements in order to form the aperture which sends and receives the ultra wave is provided, as for element selective expedient 22, are divided into the plural groups which consist of the plural drive vibrating elements which 1 or it adjoins the plural drive vibrating elements according to the depth of the focusing point.フォーカスデータ数の増大を抑制しつつ、ビーム幅を絞るのにより好適な超音波診断装置を実現するため、被検体との間で超音波を送受する超音波探触子10と、超音波探触子10に駆動信号を供給する送信手段12と、超音波探触子10から出力される受信信号を処理する受信手段16と、受信手段16から出力される信号に基づき超音波像を再構成する手段18と、超音波像を表示する手段20とを備え、超音波探触子10を構成する超音波と電気信号を相互に変換する複数の振動要素のうち、超音波を送受する口径を形成するための複数の駆動振動要素を選択する素子選択手段22を設け、素子選択手段22は、フォーカス点の深度に応じて複数の駆動振動要素を1又は隣接する複数の駆動振動要素からなる複数の組に分ける。
