An automatic and miniaturized injector and sample-taker device (1) for medicaluse comprises an enclosure (2) and at least one needle (15) movable relative tosaid enclosure (2). The injector and sample-taker device includes a detectorsystem (12) suitable for detecting the presence of a blood vessel in a predeterminedvolume a control unit (7) suitable for controlling the displacement of the needleas a function of information provided by said detector system (12) and at leastone reservoir (13) for containing a substance for injection or to be taken.
