An inspection probe includes a vibration transmission portion transmitting an ultrasonic vibration along a longitudinal axis, and a vibration damping portion continuous with a distal direction side of the vibration transmission portion. the vibration damping portion damps the ultrasonic vibration by causing vibration energy of the ultrasonic vibration to be lost and converting the lost vibration energy to heat energy in a state that the vibration damping portion vibrates in a manner to follow the vibration transmission portion. An index section of the inspection probe serves as an index indicating a conversion amount to the heat energy in the vibration damping portion.
