Besides methane adsorbed in porous system of coal, a considerable part is dissolved (absorbed) in macromolecular coal matrix. This part is usually included within the adsorbed methane without discerning the two different types of binding, which is of importance particularly at the gas-bearing assessment. Analysis of the complete sorption isotherm including both processes enabled to derive proportion of the adsorbed and desorbed methane from position and shape of the desorption branch of the isotherm. This analysis has shown that the amount absorbed exceeds the amount adsorbed both for bituminous and brown coal. The absorption in the macromolecular structure of coal matrix represents the fifth type of methane binding in coal. Measuring was carried out by gravimetric method. (C) 2004 Elsevier Ltd. All rights reserved.