We have performed EELS analysis of poly(methyl metacrylate) (PMMA) in the analytical TEM in order to evaluate the possibility to obtain chemical information on electron sensitive polymers. In the acquired spectra, we propose an identification to the different chemical bondings in agreement with molecular orbital calculations and with previous XANES experiments. Moreover, main results confirm that PMMA is very sensitive to electrons with a critical dose of about 10(2) C m(-2). The evolution of the EELS spectra of PMMA during irradiation damage is found to be slightly dependant on the molecular weight of the polymer. Finally, a degradation process in agreement with EELS data is proposed.