The dynamic features of soot combustion on a single layer, planar diesel particulate filter (DPF) were studied using IR imaging. At a feed temperature of 635 degrees C, the soot combustion rate was uniform all over the surface at low oxygen concentrations. At higher oxygen concentrations, local ignition occurred at either one or several locations. The maximum temperature rise of the moving fronts (> 100 degrees C) was much higher than those attained during uniform combustion. The temperature fronts bounding an ignited zone propagated on the surface. Their peak temperature and velocity changed as they moved on the surface. The maximum temperature of a downstream moving front exceeded that of the corresponding one moving upstream. At a soot loading of 10 g/L, a hot zone formed close to the end of the DPF and the bounding temperature front propagated upstream until it conquered the whole surface. At a soot loading of 20 g/L, the position and number of the hot zones strongly depended on the oxygen concentration. In general, increasing either the oxygen concentration or the soot load increased the moving front temperature and velocity. The flow rate affected the location of the ignition point for soot loading of 10 g/L but not for 20 g/L.