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