A medical device and method are disclosed, which can sufficiently capture a capturing target even if a lumen is deformed. A medical device has an accommodation unit and an impeller holding unit. The accommodation unit includes a lumen which accommodates a capturing target present inside a living body, in which a shape of at least a portion on a distal side is deformable, and whose inner surface before and after deformation is configured to be flat as a whole, a distal opening portion and a proximal opening portion which respectively communicate with the lumen, and a filter for capturing at least one or more of the capturing targets. The impeller holding unit includes an impeller which causes a fluid to flow from the distal opening portion toward the proximal opening portion inside the living body so as to allow the lumen to aspirate the capturing target together with the fluid.