The automatic pressure device for this ultrasonic diagnostic device as for (3), in order the probe (2) the applied part which installation and removal unrestrictedly is installed (31) with, the applied part that with the probe which is installed the ultrasonic sending and receiving aspect of that probe (27) to make advance and retreat possible, the grip section which sliding freely is installed (32) with the probe holder which it possesses (21) with, the tube body of the flexibiility where one end is locked to the grip section of probe holder (41) with passes by the tube body and the inner cable where one end is connected to the applied part (42) with the power transmission wire which it possesses (23) with, powerOther than the tube body of the transmission wire the edge is locked, other than the inner cable connecting the edge and the pressure power expedient which it moves (24) having is constituted. Therefore, the selfishness to use and be good, be able to remove the influence of electromagnetic wave noise, at the same time through the motor and the spring etc, the automatic pressure device which can add the pressure which is stabilized to the suffering inspection body body chart is actualized.本超音波診断装置用の自動圧迫装置(3)は、探触子(2)が着脱自在に装着される装着部(31)と、装着部がその装着された探触子と共にその探触子の超音波送受信面(27)を進退可能とするように摺動自由に装着される把持部(32)とを有する探触子保持具(21)と、探触子保持具の把持部に一端が固定された可撓性の筒体(41)と筒体に挿通され装着部に一端が連結されたインナーワイヤ(42)とを有する動力伝達ワイヤ(23)と、動力伝達ワイヤの筒体の他端が固定され、インナーワイヤの他端を連結して進退させる圧迫動力手段(24)を備えて構成される。従って、使い勝手がよく、電磁波ノイズの影響を排除でき、かつモータ、ばね等を介して安定した圧迫を被検体体表に加えることができる自動圧迫装置が実現される。