The removal of carbonaceous deposits formed during the conversion of methanol to hydrocarbons on zeolite H-ZSM-5 was investigated in a thermobalance system coupled with an IR spectrometer. Using different carrier gases, the effect of thermal treatment increased in the order helium<hydrogen<propane. Up to 20% of the total amount of coke was released by the treatment with propane. The coke remaining on the zeolite is hydrogen-deficient in nature, as shown by temperature-programmed oxidation. The interaction of coke with molecular hydrogen was studied by H/D exchange. Furthermore, from isotope labelling, no evidence of carboxylate-like bonds between coke species and the zeolite surface was found.