The Experimental Pressurized Fluidized Bed Combustor, which has been built as an extension to the National Coal Board Power Station, which is adjacent to Grimethorpe Colliery, Yorkshire, England, is described in this report. The Governments of the United Kingdom, the United States of America and the Federal Republic of Germany, under the auspices of the International Energy Agency, have agreed to share equally between them the costs of building and operating the plant. Control of the project was vested in an Executive Committee consisting of one representative of each Government with all decisions requiring unanimity. The actual operation of the project was vested in an Operating Agent, NCB (IEA Services) Ltd., a wholly owned subsidiary of the National Coal Board. The Implementing Agreement envisages a seven year project to be executed in four stages: (1) Procurement of Design Study with accompanying tender documents. (2) Tendering for construction of the Plant; study of appraisal of tenders. (3) Construction and acceptance of the Plant. (4) Operation of the Plant. The project is now towards the end of Stage 3. Construction has been completed and commissioning is in progress to prepare the plant for the start of the operational phase in Autumn 1981. Because of the confidentiality of much of the design information, for the purposes of this report technical descriptions have been confined to that of a general appraisal.