The theory of micropore volume filling has been modified in taking int
o account the adsorbate compressibility. A new equation has been obtai
ned for calculating the micropore volume from the experimental value o
f the limit of adsorption. The estimations, with the example of benzen
e adsorption on activated carbons, show that because of the adsorbate
compressibility, the real micropore volume can exceed the values calcu
lated from the conventional Dubinin-Radushkevich theory by about 10% a
t room temperature, and this difference increases with an increase in
temperature.