Abstract: A screw type fixture is disclosed. In the fixture of the present invention, small screw threads (231) are formed on a ridge of a large screw thread (233) formed on the circumferential outer surface of the fixture, so that reliable fixing force of the fixture to cancellous bone is ensured by the increased contact surface, and stress around the large screw thread (233) is distributed. Furthermore, in the present invention, the pitch of the screw thread of a cortical bone coupling part (33) of the fixture, which is implanted in cortical bone, and the difference between the outer diameter thereof and the root diameter thereof are less than those of a cancellous bone coupling part (34) of the fixture, so that stress otherwise concentrated on the cortical bone is distributed to the cancellous bone, thus preventing bone resorption, and promoting osseointegration.