The idea of writing this book orIgmates from a suggestion of Bernard Sapoval: "Why don't you write it?" he asked. "Coulomb screening is a problem that everybody encounters in many different contexts, and there is no textbook that gathers the various aspects ofthe subject. " The content ofthe book, in a shorter form, was first taught for four years as a course in Dipl6me d'Etudes Approfondies Sciences des Materiaux, headed by Prof. J. -F. Petroff, at Paris VI University. The present extended version was written after discussions with Alia Margolina-Litvin. An essential feature of screening is...