The automatic injector (1) it showed this invention, the long housing where as for this automatic injector (1), as the hollow injection needle (6) and stopper (13) the syringe which it has included (5), it was laid out the long housing (2), the syringe (5), sleeve the syringe carrier (4) was laid out unrestrictedly inside vis-a-vis the housing (2) at the time (2) and - activation: Region to for interposing the housing (2) it passes by the orifice from cover position inside and the proximal edge (P) exceeds and pushes the needle (6) to ahead position, the medicine (M) it manipulates the syringe (5) in order to inject dosage, the medicine (M) after delivering at least partly, it covers and to with position it has the needle (6) the syringe which can pull back (5), in order the single compressed spring (7) with, before the - manual operation spring means (7) to lock in compressed state, to be laid out, at the time of manual operation for injecting the compressed spring (7) it is possible to release, it has activation means (3). The thrust tube (8) through, the plunger (9), in order the compressed spring (7) from the load the syringe (5) and/or stopper (13) to transmit, the 1st screw thread where it is laid out, the thrust tube (8), in order for revolution to be restrained vis-a-vis the housing (2), it is laid out, the thrust tube (8) and the plunger (9), at least regarding initial state in order to be engaged possesses the 1st direction which is laid out and corresponds (9.3) and the 2nd screw thread (8.2) it displays. The plunger (9), when removing the automatic injector (1) from the injection region, in order the 1st screw thread to correspond due to the fact that revolution is released, the plunger (9) as a revolution, and a result (9.3) and the 2nd screw thread (8.2) to bring engagement release, it is laid out. The thrust tube (8), furthermore it advances side by side exercises, possesses corresponds converse direction and to 1st direction the 4th screw thread whic
