There is provided a lancet pricking device, comprising a lancet, a launching spring, a trigger part and a holder for housing therein the lancet, the launching spring and the trigger part. In the lancet pricking device, the lancet comprises a lancet body, a lancet cap and a pricking needle, and the pricking needle is disposed in both the lancet body and the lancet cap, and the trigger part has a pair of arms positioned inside the holder, and the launching spring is attached to the lancet body, and the lancet body is secured to the arms of the trigger part by an abutment of the lancet body on the arms such that the launching spring is kept compressed before a pricking operation. In such lancet pricking device, the trigger part cannot be pushed toward the inside of the holder at a point in time before the lancet cap is removed, and whereas the trigger part can be pushed toward the inside of the holder at a point in time after the lancet cap is removed, and thus the lancet body becomes capable of warping upon being pressed from an outside to cause the secured lancet body to be released.
