The invention relates to a device for dispensing a liquid gas formulation in a metered manner, wherein the device is particularly suited for use as an injection system in nail driving devices and comprises a pressure-stable container having a flanged rim, to which a valve cover containing a dispensing valve is tightly fastened. The container is equipped with two separated chambers, one of which receives the liquid gas formulation and communicates with the dispensing valve and the other of which contains a driving medium under over-pressure. A piston, which can be moved in a sealing manner and which divides the container into the two chambers, is provided in the container. The driving medium is compressed air in combination with a small amount of liquid gas formulation. The flanged rim of the container is designed as an inner flanging. The piston is equipped with a one-way valve arrangement, which allows liquid gas formulation to overflow from the chamber containing the liquid gas formulation into the chamber containing the driving medium. The dispensing device is particularly inexpensive to design and can be cheaply produced and filled in a very simple manner.