The invention relates to a disposable injector with a housing, with a cylinder/piston unit which is arranged thereon and has a manually movable piston, and with a detachable container adapter mounted upstream of this cylinder/piston unit, wherein the container adapter supports a container that is closed by an openable stopper. The piston of the cylinder/piston unit is movable via a pump rod. The container adapter engages at the front end around the cylinder of the piston/cylinder unit. The container adapter has an intermediate floor which supports a dual adapter having at least one through-channel. The container, which bears tightly with its stopper on the dual adapter, sits longitudinally displaceably in the rear of the container adapter. The container is opened by displacing it towards the intermediate floor and pushing the stopper into the container.With the present invention, a disposable injector is developed which stores a liquid and an active substance in each case separately and in a sterile manner and provides a space in which the active substance, for its application, is dissolved in the liquid or mixed with the liquid.
