The invention refers to an auto-injector (1) for administering a medicament (M) and to a method for operating it, the auto-injector (1) comprising: a tubular chassis (2) and a carrier subassembly, comprising a tubular carrier (7) slidably arranged in the chassis (2). The carrier (7) contains a syringe (3), a drive spring (8) and a plunger (9) for forwarding load of the drive spring (8) to a stopper (6) arranged in the syringe (3). The syringe (3) is locked for joint axial translation with the carrier (7). A control spring (19) is connectable to the carrier (7) by first interlock means (20, 23, 24) for needle insertion, wherein the whole carrier subassembly is advanced. Second interlock means (11, 13, 15) are arranged for releasing the drive spring (8) when the carrier (7) has at least almost reached an injection depth thus delivering the medicament (M). The first interlock means (20, 23, 24) are arranged for decoupling the control spring (8) from the carrier (7) and coupling it to the chassis (2) for advancing it over the needle (4) into a needle safe position.本發明表示一種用以供給一藥劑(M)之自動注射器(1)以及一種操作自動注射器(1)之方法，該自動注射器(1)包含：一管狀機架(2)及一載體子元件，包含一可滑動地配置在機架(2)中之管狀載體(7)。載體(7)包含一注射器(3)、一驅動彈簧(8)以及一用以將驅動彈簧(8)之負載轉遞至配置在注射器(3)中之阻塞器(6)之柱塞(9)。注射器(3)係被鎖扣以供與載體(7)聯合軸向平移。一控制彈簧(19)係藉由第一聯鎖機構(20、23、24)而可連接至載體(7)以供針部插入，其中整個載體子元件係被推進。第二聯鎖機構(11、13、15)係被配置成用以在載體(7)已至少幾乎到達一注射深度時釋放驅動彈簧(8)，從而輸送藥劑(M)。第一聯鎖機構(20、23、24)係被配置成用以使控制彈簧(8)與載體(7)分離，並將其耦接至機架(2)，用以將其推進超過針部(4)進入一針部安全位置中。
