Ultrasound endoscope

An ultrasound endoscope includes: an insertion portion to be inserted into a subject; an ultrasound transducer that is provided at a distal end of the insertion portion and includes plural piezoelectric element groups configured to transmit and receive ultrasound; a connector portion that is provided on a proximal end side of the insertion portion and includes plural connectors to which an external device is connected; and a cable portion including plural first coaxial lines connected to the piezoelectric element groups configured to transmit the ultrasound to a first area, and plural second coaxial lines connected to the piezoelectric element groups configured to transmit the ultrasound to a second area, the first coaxial lines being shorter in length than the second coaxial lines, the first area and the second area being where the ultrasound is transmitted.