Abstract: An autoinjector for replaceable containers of syringe type, comprising a barrel of axially roughly constant cross-section, a front opening with or for an injection needle and at least one movable rear piston, optionally with a plunger connected thereto, inserted in the barrel for the displacement of a container content, the autoinjector comprising a) a housing, b) a container carrier, arranged for reception of the container and arranged movably in relation to the housing in container axial direction between a rear, needle-covering, position and a forward, needle-exposing, position, c) an autopenetration mechanism, comprising at least a penetration head and a penetration drive, the penetration head being arranged for movement of the barrel or carrier in the forward direction and the penetration drive being operable to apply force between the housing and the penetration head, d) an autoinjection mechanism, comprising at least an injection head and an injection drive, the injection head being arranged for moveme