An adjustment apparatus is used for ultrasound examination of a subject by transmitting ultrasound to the subject and receiving the ultrasound reflected from the subject. The apparatus includes: a change unit configured such that one end is connected to a suction pump and the other end is provided at a portion of a channel leading to a contact portion with the subject, to change suction force of the suction pump on the other end; and a damper for suppressing change in the suction force. The change unit includes: a cylinder having first and second portions for communicating with one end side and the other end side of the channel, respectively; a piston slidable in the cylinder to change a communication state between the first and second portions; and a spring for biasing the piston toward a direction of causing the first and second portions not to communicate with each other.