An ultrasound probe includes: an ultrasound transmitting and receiving unit provided on an insertion portion configured to be inserted into a subject, the ultrasound transmitting and receiving unit having a plurality of piezoelectric elements annularly arrayed to transmit ultrasound to the subject and receive an ultrasound echo reflected from the subject; a balloon locking portion attached on a distal end side of the ultrasound transmitting and receiving unit and having a groove portion for locking an opening end part of a balloon that covers the ultrasound transmitting and receiving unit, the balloon locking portion being formed of metal or carbon, the balloon locking portion having, on an outer periphery thereof, a depression leading to the groove portion; and an insulating portion provided between the ultrasound transmitting and receiving unit and the balloon locking portion, the insulating portion being formed of insulating material.