Microelement (mineral) composition of the particulate matter emitted from fires in boreal forest was investigated by X-ray fluorescence analysis using synchrotron radiation (the XRF SR method). About twenty different chemical elements with atomic numbers from potassium K and higher were detected and measured quantitatively in the aerosol particles sampled. Total microelement (mineral) fraction was estimated to be about 5-10% of the total particulate matter. Both the total particulate matter emission and the mineral one were evaluated for fires in boreal forests of Siberia.