NOVELTY - The material to be deposited (4) is vaporized twice. A first unit (2) vaporizes the material at a first location (3) close to a moveable intermediate carrier (5). The material is deposited onto the carrier, coating it. The coated carrier is moved to a second location (6) close to the substrate to be coated (8). Here the material on the carrier is vaporized a second time and deposited onto the substrate.    USE - Vacuum-deposition plant producing e.g. organic light-emitting diodes or organic solar cells.    ADVANTAGE - The new process produces higher yields when coating substrates with vaporized materials. When co-depositing vaporized materials, constant, reproducible stoichiometry is achieved within the layer, throughout the entire coating process. Yields of 90% are achieved, greatly improving over cited prior art. Close spacing is achieved. High yields prevent waste of costly organic materials. Unlike the case when using known line sources, the new method can be used for even narrow substrates. Several materials may be vaporized simultaneously.    DETAILED DESCRIPTION - The intermediate carrier is a continuous belt or rotary disc. It is cooled (9) near the first vaporization unit. A heater (7) on the opposite side of the carrier performs the second vaporization, over an interval of 0.001 - 10 seconds. In a development based on the foregoing principles, two materials are deposited on the belt in succession. On re-vaporization at the final deposition location, the two materials mix. This takes place predominantly in the vapor phase, immediately before deposition onto the substrate. The mixture is formed and deposited in constant, stoichiometric proportions. The material vaporized is organic. A metal is vaporized. The length of the first vaporization unit is proportional to the layer thickness of material deposited onto the belt. A continuous steel belt is used; it is 10-500 mu m thick. Alternatively a rotary quartz disc coated with silicon carbide to a thickness of 2-100 mu m is used as the carrier. The rotary disc is alternatively made from a material of low relative magnetic permeability. A layer with high relative magnetic permeability is coated onto the surface facing the first vaporization unit. The spacing between substrate and intermediate carrier is less than 50 mm, preferably less than 5 mm. The final heater (7) is a laser source, an induction heater or an electron beam source. AN INDEPENDENT CLAIM IS INCLUDED FOR corresponding vacuum-deposition equipment.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic side view of the plant.    first vaporization unit (2)    first location (3)    material to be deposited (4)    moveable intermediate carrier (5)    second location (6)    re-vaporization heater (7)    substrate to be coated (8)    cooler (9)