This self-contained book takes the reader on a journey from the basic facts about atoms to topics at the forefront of current condensed matter research, giving students a broad view of materials science. The contents grew out of the lectures on solid state physics given to both theorists and experimentalists in the US who had little previous background in the area. The topics are of direct relevance for the interpretation of experimental data. Even if they may not be of chronological order, their universality is emphasized. The mathematics is simplified without sacrificing precision, providing an intuitive understanding of the phenomena discussed. The book is easily accessible to any mathematically inclined scientist or engineer with a basic knowledge of quantum mechanics.