Semiconductor component manufacturing plant with ventilated false floor

A semiconductor component manufacturing plant, in a building having an upper storey and a lower storey separated from one another by a support slab having an upper face and a lower face and supporting a false floor formed from a juxtaposition of false floor plates having an upper face and a lower face, with at least one process chamber placed in the upper storey which in itself constitutes a clean room, and with vacuum generation means for generating and maintaining a controlled vacuum in the process chamber, the vacuum generation means being at least in part placed in an intermediate space situated between the support slab and the false floor, the false floor plates having through passages between their upper face and their lower face, the support slab having passageway openings between its upper face and its lower face, wherein suction means are provided in the lower storey for sucking the atmosphere from the clean room to the lower storey, producing a gaseous flow which travels in the through passages of the false floor plates to the intermediate space, around the vacuum generation means in the intermediate space, and in the passageway openings of the support slab to the lower storey.