EBES4 is an electron-beam exposure machine designed for accurate submicron lithography with good throughput. It can write on optical and x-ray mask substrates and directly on semiconductor substrates. Standard pattern data are preprocessed using a special purpose processor to remove overlap and to reverse the tone if required. The address size can be varied from 1/16 to 1/8 μm. Patterns are written by first breaking them into microfigures which can be rectangles, parallelograms, or 45° triangles with a maximum size of 16×16 addresses. Each microfigure is positioned on the continuously moving substrate using magnetic and electrostatic deflection systems. They are written by stepping in a raster with a 1/8 μm spot using an additional very high speed electrostatic deflection system. The coordinate system can be distorted by digital hardware to correct for mechanical errors or to register with another lithography level. The electron-beam column with its thermal-field-emission gun, the hydraulic stage, the mask-handling robot, the control system, and the pattern data flow are all described. The system is highly automated, and the pattern data flow, electron-beam column setup, vacuum system switching, and cassette handling are all under the control of a VAXTM 11/780. Distributed processors are used for lower level control tasks. Resists of up to 8 μC cm−2 can be exposed at a rate of one 4 in. mask (containing 109 microfigures) every 30 min at 1/8 μm address size, while resists requiring 20 μC cm−2 can be exposed at a rate of one every 50 min. No damaging heating effects have been observed.