To provide an ultrasonic diagnostic apparatus that has achieved a TGC circuit suitable for being mounted on a 2D array probe, and a probe used for the ultrasonic diagnostic apparatus.SOLUTION: A probe for transmitting an ultrasonic wave to a diagnostic site and receiving a reception signal, which is a reflection wave, includes: a plurality of vibrators； a plurality of low noise amplifying circuits corresponding to each of the plurality of vibrators； and a single differential converter for converting a control signal that rises with a lapse of time to a first bias signal that rises with a lapse of time and a second bias signal that declines with a lapse of time, and controlling the plurality of low noise amplifying circuits. The low noise amplifying circuit includes: an attenuator for attenuating an electric signal from the vibrator； a first amplifying circuit for amplifying an output signal of the attenuator so as to become gradually larger with a lapse of time by the first bias signal； a second amplifying circuit for amplifying the output signal so as to become gradually smaller with a lapse of time by the second bias signal； and a subtractor for subtracting the output of the first and second amplifying circuits.SELECTED DRAWING: Figure 1【課題】 ２Ｄアレイ探触子への搭載に適したＴＧＣ回路を実現した超音波診断装置、及びそれに用いる探触子を提供する。【解決手段】 診断部位に超音波を送信し反射波である受信信号を受信する探触子であって、複数の振動子と、複数の振動子のそれぞれに対応した複数の低雑音増幅回路と、時間の経過と共に上昇する制御信号を時間経過と共に上昇する第１のバイアス信号と時間経過と共に下降する第２のバイアス信号とに変換し複数の低雑音増幅回路を制御するシングル差動変換器とを有し、低雑音増幅回路は、振動子からの電気信号を減衰させる減衰器と、減衰器の出力信号を第１のバイアス信号により時間経過と共に徐々に大きくなるように増幅する第１の増幅回路と、第２のバイアス信号により時間経過と共に徐々に小さくなるように増幅する第２の増幅回路と、第１と第２の増幅回路の出力を減算する減算器を備える。【選択図】図１
