A new hydroxylammonium compound (NH3OH)(2)GeF6, has been synthesized by the addition of solid NH3OHF to a solution of GeO2 dissolved in 20% HE The compound was characterized by chemical analysis and X-ray powder diffraction, the thermal decomposition was studied by thermal analysis and mass spectrometry. (NH3OH)(2)GeF6 crystallizes monoclinic. Two endothermic and two exothermic peaks have been observed on the DSC curve, the decomposition product at 500 degreesC is GeO2. (C) 2004 Elsevier B.V. All rights reserved.