An endoscope includes an insertion part that includes a distal end and a proximal end, a distal-end-portion body that is provided on a distal end side of the insertion part, and an ultrasound transducer that is provided on a distal end side of the distal-end-portion body. The distal-end-portion body includes a pair of walls, a standing base that is disposed in a space formed by the pair of walls and connected to a treatment tool outlet, an observation window that is disposed on one wall of the pair of walls, and a nozzle that is provided on the flat surface opposite to the space across the observation window and ejects washing water to the observation window. The wall surface of the other wall of the pair of walls is positioned on an extension of an ejection direction of the washing water to be ejected from the nozzle.