Etching of tungsten and fused silica induced by a focused argon-ion laser beam lambda = 514 nm has been investigated on a composite consisting of a thin W-layer sputtered onto a fused silica substrate. Pure WF6 gas serves as the reactant for both Wand silica-etching. The process starts with pure chemical etching of tungsten. As the thin W-layer is etched through, it continues as a combination of etching of both tungsten and silica. The latter is most probably caused by the formation of fluorine radicals at high temperatures. The analysis of the process is supported by theoretical estimations of temperatures and of the profile evolution of the etched holes. (C) 2002 Elsevier Science B.V. All rights reserved.