Coal combustion under oxy-fuel conditions shows significant differences to combustion in air. Examinations on the single-grain level give detailed insight into the combustion phenomena of ignition, volatile combustion, and char burnout and, therefore, provide the fundamentals for the development of large-scale oxy-fuel facilities. The combustion of a hard coal in a size fraction of d(p) = 90-125 mu m was investigated in a laminar flow reactor at a temperature of 1.500 K. The gaseous fuel oxidizer contained 3% O-2 by volume and CO2 or N-2 as diluents. A third measurement In a CO2-rich atmosphere containing 9% O-2 is also presented to show the influence Of 02 concentration. Particle temperatures were measured for three residence times with an imaging two-color pyrometer.