AbstractThe `Super-ASHURA' KrF laser system is currently under development at the Electrotechnical Laboratory. An electron-beam pumped large-aperture KrF laser amplifier named `Amp4' has been completed and is operational as the main amplifier. Amp4 and the currently operating `ASHURA' pre-amplifiers (660 J, six beams) have been combined to form the upgraded system. Laser energy extraction experiments from Amp4 have been started (2.3 kJ, 12 beams).