A dedicated experimental facility has been constructed to simulate, in controlled conditions, the contamination by multielement aerosols of various agro-ecosystems typical of Europe. Large monoliths of undisturbed soils (12 t each) have been sampled throughout Europe; the extraction method used in order not to destroy the pedological zones is described. These monoliths are installed in the facility greenhouses under computer-driven climatic and hydric conditions, which mimic those of their origin. A critical comparison of the climatic values in the greenhouse and in the original sites is done. Contamination of the lysimeters is performed with a specific furnace capable of generating radioactive and stable aerosols. The general characteristic aerosols are determined. They are representative of those that would be released in the case of a severe accident in a pressurized water reactor with core fusion (2950°C).