The textural and chemical surface properties of two glassy carbons (P1 and P2) obtained by carbonization of furfuryl alcohol polymers are studied. The change in these properties after their treatment with oxygen microwave plasma was also determined. One of the samples (P2) has a molecular sieve character for the N2/CO2couple, whereas the other (P1) has a molecular sieve character for the benzene/cyclohexane couple. The treatment with oxygen microwave plasma modifies the textural characteristics to a variable extent depending on the degree of treatment, although the molecular sieve characters remain unchanged in both cases. Moreover, the treatment produces an increase in phenolic and carbonate structures in P2 and also an increase in phenolic and ether structures in P1.