PROBLEM TO BE SOLVED: To stabilize the amount of reflection of an ultrasonic transducer in an optical image while reducing the diameter of the tip of an insertion portion. SOLUTION: An ultrasonic endoscope is provided with a hard part 211 provided on the tip side of an insertion part 21 to be inserted into a subject and an observation optical system provided on the hard part 211 for observing an object. And an ultrasonic transducer module 70 having an ultrasonic transducer 7 capable of transmitting and receiving ultrasonic waves, and an ultrasonic transducer at a position where at least a part of the ultrasonic transducer module 70 is included in a part of the field of view of the observation optical system. A screw 218a that can adjust and fix the position of the vibrator module 70 with respect to the hard portion 211. [Selection diagram] Fig. 4【課題】挿入部の先端部分を細径化しつつ、光学画像内での超音波振動子の映り込み量を安定化させること。【解決手段】超音波内視鏡は、被検体内に挿入される挿入部２１の先端側に設けられた硬質部２１１と、硬質部２１１に設けられ、対象物を観察するための観察光学系と、超音波を送受信可能な超音波振動子７を有する超音波振動子モジュール７０と、観察光学系の視野の一部に超音波振動子モジュール７０の少なくとも一部が含まれる位置に、超音波振動子モジュール７０の硬質部２１１に対する位置を調整して固定可能なビス２１８ａと、を備える。【選択図】図４
