This text explains the fundamental links between solid state phenomena and the basic laws of quantum mechanics, electromagnetism and thermodynamics. Its detailed discussion of electron and photon states are used to illuminate thermodynamic, electric, magnetic and optical phenomena, stressing their relation to the basic laws of physics. Several important experiments are also included, showing the experimental roots of the subject, important underlying concepts, and illustrating how fundamental qualities can be measured. Throughout, numerical calculations are emphasized for the purpose of determining the sizes of various important qualities. Many worked examples are also included, as well as a wide variety of problems to test comprehension of all topics covered. Also contains a special chapter on the physics of semiconductor devices. Features extensive reading lists at the chapter-ends. Except for engstroms and electron volts, SI units are used extensively.