Abstract: A lancet assembly includes a lancet and a lancet holder that houses the lancet, wherein the lancet includes a lancet body, a lancet cap and a pricking component, the pricking component is situated in both of the lancet body and the lancet cap, the tip of the pricking component is covered with the lancet cap, and the lancet cap and the lancet body are integrally connected together by a bridging component when the lancet cap is pressed in the pricking direction with the lancet body attached to the lancet holder, the bridging component is broken so that the lancet cap is separated from the lancet body. Thereafter, when the separated lancet cap is pressed further: in the pricking direction, the separated lancet cap moves to a position that is off the pricking pathway of the pricking component.

Abstract: There is provided the pricking device that allows it to load the unspent lancet assembly into the injector, and that inhibits loading of the unspent lancet assembly into the injector. The pricking device has the notched portion formed on the edge of the opening end of the lancet holder, and the plate spring component is provided on the inner wall of the housing of the injector. One end of the plate spring component is secured to the injector housing, whereas the other end of plate spring component is free end, and the tip end portion of the free end being provided with the hook-shaped portion. In the spent lancet assembly, the notched portion engages with the hook-shaped portion so that the loading becomes impossible.