The relation between beam properties and minimum linewidth for a rectangular electron beam for submicron lithography is obtained through experiments and electron scattering simulation. Patterns are exposed in a 0.5‐μm‐thick PMMA resist film on a silicon wafer. The result gives a guiding principle in designing an electron‐optical column of a rectangular electron‐beam exposure system. A minimum linewidth of 0.5 μm can be obtained using a beam with a beam edge width δ=0. 18 μm at a beam voltageVa=25 kV and 0.2‐μm minimum linewidth using a beam with δ=0.08 μm atVa=30 kV.