Abstract: A lancet assembly includes a lancet, a lancet engaging part, and a lancet case housing the lancet and the lancet engaging part. In the lancet assembly of the present invention, the lancet engaging part and the lancet cap are disposed such that they are capable of making contact with each other. When the lancet engaging part is forced to move forward with respect to the lancet in a pricking direction, the lancet cap is pressed by the lancet engaging part, and thereby the bridging component is broken so that the lancet cap is separated from the lancet body. When the lancet engaging part is forced to further move forward, the separated lancet cap moves to the position off a pricking pathway of the pricking component within the lancet case.