A lancet assembly includes a lancet and a lancet holder that houses the lancet, whereinthe 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 componentwhen 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.
