By actually measuring the pressure of the ultrasonic scanning region, and to provide an ultrasonic diagnostic device for determining the elastic modulus high accuracy. A pressure bag installed on the ultrasonic transmitting and receiving surface of the ultrasonic probe, the liquid is filled, and means leaving the liquid injection inflate or deflate the pressure bag let out injecting the liquid into the compression bag, wherein a pressure measuring means for measuring the pressure of the liquid filled in the compression bag, based on the pressure information measured by the pressure measuring means, and calculates the pressure of the ultrasonic scanning region of the object in contact with the compression bag and a pressure calculating means, wherein the elasticity information calculating means calculates elasticity modulus using the pressure information.超音波走査領域の圧力を実測することにより、精度が高い弾性率を求める超音波診断装置を提供する。前記超音波探触子の超音波送受信面に設置され、液体が充填される圧迫袋と、前記圧迫袋内に液体を注入出させて前記圧迫袋を膨張又は収縮させる液体注入出手段と、前記圧迫袋内に充填された液体の圧力を計測する圧力計測手段と、前記圧力計測手段で計測された圧力情報に基づいて、前記圧迫袋に接する前記被検体の超音波走査領域の圧力を演算する圧力演算手段とを備え、前記弾性情報演算手段は前記圧力情報を用いて弾性率を演算する。
