This refers to an auto Injector (1) to administer a dose of liquid Medicine (m), which comprises: a tubular chassis (2) which is Telescopic in a tubular casing (12); a subset of Carrier comprises a Carrier Tube (7) arranged on a Sliding The chassis (2) within the housing (12),The carrier (7) is adapted to contain a syringe (3) with a Hollow injection Needle (4), a Spring and a plunger Drive (8), (9) to forward the Spring load impulse (8) to (6) a Cap from the syringe (3),The syringe (3) can hold for the axial Translation together with the carrier (7); a Spring control (19) provided around the carrier (7) for moving the carrier (7) proximally (P) for the insertion of the Needle through the chassis (4) 2) at the injection siteIn the spring of control (19) available to predispose the casing (12) against the chassis (2) (d) extend distally to the chassis (2) out of the proximal End (P) of the housing (12), in which an insertion depth of the Needle (4 is defined by the carrier (7) to do CAP (2) with the chassis in a preset position,In the housing (12) provides for free or allow the release of the Spring control (19) for the insertion of the needle with the Movement of the housing (12) proximally (P) with respect to the chassis (2) against the predisposition to an advanced position.La presente se refiere a un auto-inyector (1) para administrar una dosis de un medicamento líquido (M), que comprende: un chasis tubular (2) que es telescópico en una carcasa tubular (12); un subconjunto de portador que comprende un portador tubular (7) dispuesto de manera deslizante con respecto al chasis (2) dentro de la carcasa (12), el portador (7) está adaptado para contener una jeringa (3) con una aguja de inyección hueca (4), un resorte de impulso (8) y un émbolo (9) para reenviar la carga del resorte de impulso (8) a un tapón (6) de la jeringa (3), en el que la jeringa (3) se puede trabar para la traslación axial conjunta con el portador (7); un resorte de control (19) dispuesto alreded