With a simple configuration without increasing the size of the tip, to provide an ultrasonic endoscope capable of obtaining a satisfactory elastography image. Therefore, the ultrasonic probe 17 disposed at the distal end rigid portion 10, and auxiliary water channel port 24 for ejecting the fluid from the vicinity of the projecting direction of the ultrasonic probe 17 of the ultrasonic probe 17 , an auxiliary water channel 47 which communicates with the auxiliary water channel port 24, an adjusting valve 48 for variably adjusting the flow rate of the fluid flowing through the auxiliary water channel 47 into two or more states, the ultrasonic endoscope 2 has an Configure.
