Introduction: From a First-Generation Synchrotron Radiation to an X-ray Free Electron Laser

The fruitful and remarkable research results in materials science during the past more than ten years have been continuously obtained by the advent of synchrotron radiation (SR) sources, especially the third-generation SR source. This is easily understood by considering that the SR beams provide not only five to ten orders of magnitude brilliance more in the continuum vacuum ultraviolet and X-ray regions of the electromagnetic spectrum than conventional sources, but also natural collimation, high polarization, pulsed time structure and high stability. In this paper we present a brief history of SR sources, especially in Japan to know how the SR sources developed, and a view of the future research direction regarding the use of SR beams.