The invention relates to a single-use injector having a plunger actuation means (60) which is mounted in a housing (10), which is loaded by means of a spring energy storage means, and which can be unlocked by means of a moveable release device (80), wherein the plunger actuation means can be supported by a traction rod (21) mounted in the housing. The release device comprises a casing housing (82). The casing housing comprises an upper shell and a lower shell, the separation line of which is oriented in the longitudinal direction of the single-use injector. The casing housing has a cornerless cross-section deviating from the circular shape. In addition, the housing is anti-rotationally centred in the casing housing. According to the invention, a single-use injector is developed wherein the production, assembly and handling thereof is simplified.
