The paper reports on the fate of inertinite-type chars during high temperature combustion. The aim is assessing the extent to which inertinite macerals affect combustion efficiency as measured from percentage burn-out. Char samples from three medium to high-inertinite coals varying in burn-off between 20% and 99.7% were taken from the KEMA 1 MW combustion test facility. The samples were analyzed by classical microscopy. Char particles were identified as inertinite-type by visual observation. The concentration of inertinite-type particles in char does not change significantly at intermediate stages of combustion, between 30% and 98% burnoff. When less than 2% of the original coal is left unburnt, there is a shift in char composition. Higher concentrations of large (>8 mu m) fusinoid and inertoid particles are found in the last stage of burn-out for two of three coals. During most of the time solid chars from inertinite burn at the same rate as porous chars. In the fly char, the percentage unburnt from inertinite is only slightly higher than the average unburnt from the whole coal.