A medical device and method are disclosed which can facilitate maintenance work of a filter for capturing a capturing target, and which can improve operability or convenience in the maintenance work. The medical device has an accommodation unit, an impeller holding unit, and a filter. The accommodation unit accommodates a capturing target which is present inside a living body. The impeller holding unit includes an impeller which causes a fluid to flow from a distal side toward a proximal side inside the living body so as to cause the accommodation unit to aspirate the capturing target together with the fluid. Here, the impeller holding unit is configured to be attachable to and detachable from the accommodation unit on a proximal side of the accommodation unit. The filter is arranged in the accommodation unit and/or the impeller holding unit, and captures at last one or more of the capturing target.