An ultrasound endoscope includes: an insertion portion configured to be inserted into a subject a distal end portion provided at a distal end of the insertion portion and including at least one fitting groove an ultrasound transducer unit configured to be attachable to and detachable from the distal end portion and including at least one projecting portion configured to be freely fitted into the fitting groove and projecting outside in a diameter direction K of the distal end portion and a gap for removal of the ultrasound transducer unit, the gap being formed between the projecting portion fitted in the fitting groove and the fitting groove.
