The invention relates to a driving device comprising a hand-held housing in which there is accommodated a piston member for transmitting energy to a fastening element to be driven in, an interchangeable propellant and a combustion chamber arranged between the propellant and the piston member, said combustion chamber extending preferably about a central axis (A), and an actuator by means of which the energy that is transmissible from the propellant to the piston member is variable in a settable manner, wherein a discharge channel connected to the combustion chamber can be opened by means of a movable slide of the actuator, wherein a starting position of the piston member is variable in a settable manner by means of a second actuator.