A medical device includes a longitudinal axis member, a suction member that is provided at a distal end of the longitudinal axis member, has a contact surface capable of coming into close contact with an inner wall of a bursiform cavity when inserted into the bursiform cavity, and has a plurality of communication passages that are open to the contact surface and communicate with a lumen, a suction source provided at a proximal end of the longitudinal axis member so as to be connected to the lumen, and a closing member that is provided at an axial end of the suction member, comes into contact with the opening, and airtightly seals the opening.
