This book addresses the problem of soft errors in digital integrated circuits subjected to the terrestrial natural radiation environment, providing comprehensive knowledge of the complete chain of the physics of soft errors. The text discusses particle interactions with matter, soft-error mechanisms, and instrumentation developments in environment characterization, particle detection, and real-time and accelerated tests. It describes the latest computational developments, modeling, and simulation strategies for the soft error-rate estimation in digital circuits. It also explores trends for future technological nodes and emerging devices.