A new international cooperation for the next step in the tokamak development will start in the spring 1988 by the four partners, EURATOM, Japan, USSR, and USA, under the auspices of the IAEA. The project is referred to as ITER, the acronym for International Thermonuclear Experimental Reactor, and has the goal of producing a conceptual design of the machine by the end of 1990, with the purpose to provide necessary information to the national programme or to a larger international cooperation. The scope of the project includes determination of the technical parameters of the experiment, conduct of the research and development necessary to validate the assumptions underlying the concept, and estimation of costs and time needed to build the fusion machine.