PROBLEM TO BE SOLVED: To provide a fat diagnostic ultrasound probe in which an ultrasonic wave from a main probe and an ultrasonic wave from a second probe can coaxially be applied without using a driving mechanism.SOLUTION: A probe holder 5 is inclined and arranged so that an axis line L may be incident diagonally on the axis line L where an ultrasonic signal from a main probe 2 passes straight through a propagation body 3, and a flat plate member 5a for reflecting the ultrasonic energy emitted from the second probe 4 and applying it in an extension direction of the axis line L is fixed. The flat plate member 5a is configured by causing the inclination angle of the flat plate member 5a to the axis line L and the thickness of the material for satisfying propagation conditions of the Lamb wave A0 mode to be set according to the frequency of the ultrasonic signal and the material of the propagation body 3 so that the ultrasonic signal from the main probe 2 may propagate the inside of the flat plate member 5a with propagation characteristics of a Lamb wave A0 mode and thereby pass through the flat plate member 5a and may further progress in an extension direction of the axis line L.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】主プローブからの超音波と副プローブからの超音波とを、駆動機構を用いることなく同軸状に照射することができる脂肪診断用超音波プローブを提供する。【解決手段】プローブホルダ5は、主プローブ2からの超音波信号が伝播体3を直進通過する軸線L上に、軸線Lが斜めに入射するように傾斜配置され、かつ、副プローブ4から出射される超音波エネルギーを反射して軸線Lの延長方向に照射させる平板部材5aが固定され、平板部材5aは、主プローブ2からの超音波信号がラム波A0モードの伝播特性で平板部材5a内を伝播することによって平板部材5aを通過し、さらに軸線Lの延長方向に進行することができるように、超音波信号の周波数および伝播体3の材料に応じて、ラム波A0モードの伝播条件を満たす軸線Lに対する平板部材5aの傾斜角度や材料や厚さが設定されるようにする。【選択図】図1