A blood test device using a laser as a puncture member. More specifically, in a blood test device using a laser as a puncture member, the skin can be fixed at a definite position by raising the punctured skin under negative pressure, and thus the skin is brought into close contact with a blood sensor and the laser is focused on the vicinity of the blood sensor face. Thus, it is possible to provide a blood test device of the laser puncture type in which the skin can be surely punctured while giving little pain to a patient.