Fourier transform infrared micro-scale analysis of organic matter has been applied to characterise individual petrographic components of coal. The use of an infrared microscope made it possible to study and compare different parts of a single individual grain of vitrinite. This method enables analysis of particular macerals without the need for previous separation from coals. For this purpose the polished grainy micro-sections of coal have been prepared. The results obtained indicated the progression of aromatisation in the vitrinite structure with an increase of coalification degree of the parent coals.