For the purpose of reducing radiation damage and delineating fine patterns in electron beam direct writing lithography, fundamental characteristics of a three‐layer resist using heavy metal as an intermediate layer is investigated in detail. An exposure and development simulation program, ELSIS, is extensively used to estimate resolution and linewidth control. The exposure intensity distributions for a line source are calculated to evaluate pattern delineation characteristics and degree of proximity effect in this three‐layer resist. The developed pattern profiles of positive‐type resist and absorbed energy density profiles in negative‐type resist are calculated. Some relevant experimental data also are presented. These results indicate that several advantages can be expected from this three‐layer resist, such as an apparent increase in resist sensitivity and a reduction of the interproximity effect.