A medical device includes a fine needle aspiration device and an incision device which are inserted into a body by using an endoscope, and the fine needle aspiration device includes: an injection needle； an injection needle tube which surrounds the injection needle； a first limiting unit which limits the length of the needlepoint of the injection needle protruding from the injection needle tube； a syringe which is connected to the injection needle for tissue collection and medicine injection； and a second limiting unit which limits the connection between the injection needle and the syringe； the incision device includes: a knife； a knife tube which surrounds the knife； and a third limiting unit which limits the length of the cutting edge of the knife protruding from the knife tube.
