This book highlights the properties of advanced materials suitable for realizing THz devices, circuits and systems, and processing and fabrication technologies associated with those. It also discusses some measurement techniques exclusively effective for THz regime, newly explored materials and recently developed solid-state devices for efficient generation and detection of THz waves, potentiality of metamaterials for implementing THz passive circuits and bio-sensors, and finally the future of silicon as the base material of THz devices. The book especially focuses on the recent advancements and several research issues related to THz materials and devices; it also discusses theoretical, experimental, established, and validated empirical works on these topics.