Abstract: A method is provided for visualizing a combustion process of a fuel-air mixture within a combustion chamber of an internal combustion engine. Flame light signals that are generated during the combustion of the fuel-air mixture within the combustion chamber are detected in a number of detection volumes (20) by a multi-channel optical measuring probe (2) and the light intensities of the flame light signals are evaluated and graphically visualized by an evaluating and visualizing device (5). Information concerning the position of the flame is provided by flame light signals within the detection volumes (20) and by the formation of hypotheses and by the selection of a most probable hypothesis by means of a mathematical assessment algorithm implemented in the evaluating and visualizing device (5) and are graphically visualized by the evaluating and visualizing device (5).