This is a study of the worldwide microelectronics industry - technology, economic structure, international trade, co-operative agreements, corporate strategy and government policy. The semiconductor industry is examined, explaining what it is, its peculiarities and its evolution over the relatively short time since it appeared. The growing interdependence within, and the internationalization of this industry are documented and analyzed, and the study offers an appraisal of the major factors affecting international competitiveness in microelectronics. The first part of the study concentrates on painting a picture of the industry, followed by a discussion of the technology of semiconductors, useful for understanding what goes on in this technology-driven industry. There is also information provided about the economic structure and international trade pattern of the industry. This report is a summary of a programme on Microelectronics - an industry in transition undertaken by the Center for Science and Technology Policy under the direction of Herbert I. Fusfield, supported by the Center's Corporate Membership Fund and by grants form the National Science Foundation, the North American