Insitucleaning of GaAs surfaces has been achieved at 350 °C with a novel technique employing hydrogen that is excited and dissociated using a remote Ar discharge. Reconstructed surfaces characteristic of clean, As‐stabilized GaAs surfaces have been observed with reflection high‐energy electron diffraction following the cleaning treatment. Auger electron spectroscopy analyses confirm that such a treatment removes both carbon and oxygen contamination from the surface. X‐ray photoelectron spectroscopy shows the removal of oxygen bonded to both Ga and As on the surface. Emission spectroscopy shows evidence of excited molecular and atomic hydrogen with the downstream‐excitation process.