This book is a seventh edition of an elementary text on solid state physic for seniors and beginning graduate students of physical science and enjineering. This book is an update of the sixth edition of 1986 and includes additions, improvements, and corrections made in that edition in 13 successive printings - which it was time to pull together - and a number of new topic besides. Significant advances in the field have been added or discussed more fully; thus high temperature superconductors are treated, and results of scanning tunneling microscopy are displayed; the treatment of fiber optics is expanded.There are discussions, among other topics, of nanostructures, superlattices, Bloch/Wannier levels, Zener tunneling, light-emitting diodes, and new magnetic materials. The additions have been made within a boundary condition intended to keep the text within one volume at a reasonable price.