ThisvolumecontainsthelecturenotesofthefourthschoolonMagnetismand 1 Synchrotron Radiation, held in Mittelwihr, France, from 10 to 15 October 2004. The school was meant to introduce basic knowledge on magnetism and synchrotron radiation, and to present the state-of-the-art in the important domains using synchrotron radiation-related techniques for the analysis of magnetic properties of new materials. This edition introduces the magnetism community towards the european synchrotron radiation centers. In this book the reader will ?nd: (i) three introductory chapters on the basics of magnetism, on electron sp- troscopies in a large sense, and on synchrotron radiation; (ii) four chapters on spectroscopic, di?raction, and imaging techniques for magnetic studies; (iii) three chapters on the theory and recent developments of magnetic dichroism; (iv) ?ve chapters on specialized topics (spin-dynamics, magnetism under pressure, and magnetism in mineralogy) and new magnetic materials (mo- cular magnets, and material for spin-electronics). We would like to express our thanks to the teachers who agreed to a- mate this school, and took on the di?cult job of writing the lectures. We also acknowledge the kind hospitality of the Centre de Mittelwihr and the C- munaut´ e des Communes de Ribeauvill´ e.