An ultrasound endoscope according to the present invention is an ultrasound endoscope which is inserted into a subject, is capable of acquiring an optical subject image, and is provided with an insertion portion capable of transmitting and receiving ultrasound waves, An ultrasonic transducer that emits ultrasonic waves in a direction perpendicular to the longitudinal direction of the insertion portion and scans in the circumferential direction of an axis parallel to the longitudinal direction, and is provided at the tip of the longitudinal direction of the insertion portion Front-viewing optical part on which observation light from the front-viewing side is incident from the front end of the tip, and the tip end side in the longitudinal direction of the insertion part And a side field optical unit on which observation light from a side field including a part of the field of view enters.本発明に係る超音波内視鏡は、被検体内に挿入され、光学的な被写体画像を取得可能であるとともに、超音波を送受信可能な挿入部を備えた超音波内視鏡であって、超音波を挿入部の長手方向と垂直な方向に照射して、該長手方向と平行な軸の周方向に走査する超音波振動子と、挿入部の長手方向の先端に設けられ、該長手方向の先端より前方視野からの観察光が入射する前方視野光学部と、挿入部の長手方向の先端側に設けられ、該長手方向と垂直な方向の視野であって、超音波振動子の走査面の一部を視野に含む側方視野からの観察光が入射する側方視野光学部と、を備える。
