Device (6) of needle apparatus (100) injection, wherein said device (6) needle comprising: - a housing which can be mounted in a device (1) injection, said housing comprising a first element (13) housing disposed toward a proximal end of said device (6) needle, and a second element (15) of the housing disposed toward a distal end of said device (6) needle - an element (14) disposed cutting at a proximal end of said first element (13) of the housing, said element (14) cutting one end sharpened proximal - a cannula (11) fitted to the second element (15) of the housing, said cannula (11) having a blunt proximal end and - an opening in said cannula (11) disposed at the proximal end of the first element (13) of the housing wherein the first member (13) of the housing and the second element (15) of the housing can move relative to each other between an extended position and a compressed position wherein the proximal end of the cannula (11) does not extend beyond the proximal end of the element (14) when the cutting first and second elements (13, 15) of the housing are in an extended position wherein the cannula (11) extends through the aperture of the first element (13) of the housing and bypassing the proximal end of the element (14) cutting when the first and second elements (13, 15) of the housing are in the compressed position characterized in that: the first element (13) of the housing is fitted into the second housing member and that an elastic member (12) is disposed within the housing and arranged to urge the first member (13) of the housing and the second element (15) the housing toward its extended position.Dispositivo (6) de aguja para un aparato (100) de inyección, donde dicho dispositivo (6) de aguja comprende: - un alojamiento que puede estar montado en un dispositivo (1) de inyección, comprendiendo dicho alojamiento un primer elemento (13) del alojamiento dispuesto hacia un extremo proximal de dicho dispositivo (6) de aguja, y un segundo elemento (15) del a
