The Ghent Altarpiece, painted by Jan and Hubert Van Eyck (1432) will be examined from a technical point of view. The investigations Support the restoration campaign, but will also lead to new insights about the creation of the work. Binding media, varnishes and pigments are studied with gasschromatography – mass-spectrometry, Raman spectroscopy, X-ray fluorescence, total-reflection x-ray fluorescence, X-ray diffraction and a multispectral camera is used for image analysis.