Abstract: The invention relates to a fuel-operated firing device for driving securing elements into a substrate, comprising at least one main combustion chamber for a fuel, a driving piston that can be driven out of the main combustion chamber in a firing direction by expandable gases, and a pre-chamber with which an ignition device is associated and in which a pressure acting on the main combustion chamber can build up prior to a fuel-air mixture being ignited in said main combustion chamber. In order to improve the efficacy and/or functionality during the driving in of securing elements using the fuel-operated firing device, the pre-chamber has at least two venting connections which are mutually spaced in an axial direction and which have passages that can be exposed conjointly in order to facilitate rapid venting of the pre-chamber.