The present invention relates to a lancing device, a bit more detail, the user infected patient disease that can be separate collection from the lancing device more secure a blood lancet occur during blood collection process in advance It can be prevented, which can relate to easily replace the lancet lancing device, Lancing device according to the invention is formed by the internal hollow cylindrical front include the fastening of the cylindrical portion 20, the case body is formed protruding stepped to a predetermined length (10), movably the main body case along the longitudinal direction ( inserted into the hollow 10) and the front has a lancet (lancet) 12 is fitted to the main shaft 11 is coupled, is provided on one side of the main body case 10 is fitted which the lancet 12 to the front coupling and the main shaft 11, the gap issued 13 momentarily pushed forward to trigger (trigger), is provided in the rear of the main body case 10, the lancet (12 bonded fitted to the front of the main shaft (11) ) to push the eject section (14 to separate from the main shaft 11) and the fastening section (20) and removably coupled, and a needle hole (31 presented forward the needle is projected to the outside of the lancet 12) It is formed and the front cap 30, the front side of the fastening portion 20, the main shaft with interposed said lancet (12) in the state coupled with the coupling (11) is accommodated therein, the lancing device which comprises in the inner surface of the front cap (30) is formed to each of the engaging projection 32 is projected to the left and right sides, the outer peripheral surface has left, the engaging projection, respectively the right sides (32) of the fastening section (20) that is provided with a protrusion coupled in the longitudinal direction so that it is inserted into the insertion groove 21, the engaging projection insertion groove the coupling to extend from one end of the 21 unit 20 fastened along the circumference of the outer cir
