The invention relates to a disposable injector with a housing in which are arranged a mechanical spring energy reservoir, a cylinder/piston unit, a piston-actuating ram and a trigger unit, wherein the spring-loaded piston-actuating ram is supported on the housing in a releasable manner. The housing of the injector is made from a thin-walled sheet-metal part. The sheet-metal part has at least two branches. Each branch has, at the free end thereof, an angled retaining element or a recess. The branches are elastic flexural beams which, in the middle area, are each bent in a Z-shape or S-shape to form a supporting portion for the piston-actuating ram. The contact zone situated between an individual supporting portion and the piston-actuating ram represents a wedge gear pairing that forces the respective branch outwards. With the present invention, a disposable injector is developed which, with a small overall size, comprises only a small number of components and, while being easy to handle, ensures safe storage and operation.
