An ultrasonic transducer (11) for transmitting and receiving an ultrasonic wave to and from an object to generate an ultrasonic signal, a first automatic pressing mechanism (12) for generating a pressurized displacement by applying a pressing force to the subject, An elastic image generating displacement measuring circuit (28) for measuring the image displacement amount of the subject based on the sound wave signal, a modulus of elasticity calculating circuit (29) for calculating the elastic modulus of the subject based on the displacement amount for the image, A signal waveform analysis circuit (31) for analyzing the waveform of the signal based on the displacement of the sample to acquire the maximum point and the displacement period of the displacement, and a signal waveform analysis circuit And a pressurizing mechanism control circuit (32) for causing the first automatic pressurizing mechanism (12) to pressurize at timing.被検体へ超音波を送受信して超音波信号を生成する超音波振動子(11)と、被検体に押圧力を加えて加圧変位を発生させる第1自動加圧機構(12)と、超音波信号に基づき被検体の画像用変位量を計測する弾性画像生成用変位計測回路(28)と、画像用変位量に基づき被検体の弾性率を演算する弾性率演算回路(29)と、被検体の変位に基づく信号の波形を解析して変位の極大点および変位周期を取得する信号波形解析回路(31)と、信号波形解析結果に基づき変位周期に同期して変位の極大点と同一のタイミングで第1自動加圧機構(12)に加圧を行わせる加圧機構制御回路(32)と、を備えた超音波観測システム(1)。
