Abstract: There is provided a lancet pricking device which is prevented from being re-used, and also the pricking pathway of the needle thereof is improved. The lancet pricking device comprising a lancet equipped with a pricking needle and a trigger for launching the pricking needle. The trigger comprises a first trigger part and a second trigger part disposed such as to cover the first trigger part. The lancet is in engagement with the first trigger part before the pricking needle is launched. When the second trigger part is pushed from the outside for the launching of the pricking needle, the displacement of the first trigger part is caused by the second trigger part, and thereby ceasing the engagement between the lancet and the first trigger part to launch the pricking needle.