PROBLEM TO BE SOLVED: To provide an attachment which is attached to an ultrasonic probe for transmitting and receiving an ultrasonic wave for measuring an elastic wave and an ultrasonic wave for obtaining an ultrasonic image and can apply mechanical vibration.SOLUTION: An attachment 100 is attached to an ultrasonic probe 2 for transmitting and receiving a first ultrasonic wave for creating an ultrasonic image of a measurement object T whose elasticity is measured based on an elastic wave generated with mechanical vibration applied to the surface and for transmitting and receiving a second ultrasonic wave for measuring the elastic wave, intervenes between an ultrasonic transmission and reception surface 2a of the ultrasonic probe 2 and the measurement object T, and is formed of material having ultrasonic permeability. The attachment 100 is formed with a hole part 103 opening to the measurement object T side, and a vibration application part 104 which applies mechanical vibration to a surface S of the measurement object T is provided in the hole part 103.
