The invention has an object of providing an ultrasound observation apparatus that is easily inserted and for this object the invention includes: an ultrasound transducer 21 that includes an ultrasound transmitting/receiving face 21a that transmits/receives ultrasound a holding part 22, 23 that fixedly holds the ultrasound transducer an insertion portion 12 formed in a rigid cylindrical shape in which the holding part is fixedly installed at a distal end and an insertion assisting instrument 31 that is formed in a rigid rod shape or cylindrical shape, and that is insertedly disposed in a freely insertable/extractable manner in the insertion portion wherein: the holding part is fixedly installed at the distal end of the insertion portion so as to form a shape that is curved with a predetermined angle in a separating direction with respect to a longitudinal direction from the distal end of the insertion portion and a curvature angle of the holding part with respect to the longitudinal direction of the insertion portion is set so that, when the insertion assisting instrument is insertedly disposed in the insertion portion, an extension line of a straight line that contacts a distal end face of the insertion assisting instrument contacts the ultrasound transmitting/receiving face.本発明は、挿入が容易な超音波観察装置を提供することを目的とし、そのために超音波を送受信する超音波送受信面21aを有する超音波振動子21と、超音波振動子を固定保持する保持部22,23と、保持部が先端に固設され硬性の筒状に形成される挿入部12と、硬性の棒状若しくは筒状に形成され挿入部に対し挿脱自在に挿通配置される挿入補助具31とを具備し、保持部は挿入部の先端から長軸方向に対して離間する方向に所定の角度をもって屈曲した形状となるように挿入部の先端に固設されており、挿入部に挿入補助具を挿通配置したとき挿入補助具の先端面に接する直線の延長線が超音波送受信面に接するように挿入部の長軸方向に対する保持部の屈曲角度が設定されている。
