This book focuses on the technologies of the floating body cell (FBC), which is regarded as the most probable candidate to replace the conventional 1T-1C DRAM. It covers basic principles, procedures for device structure optimization, operational methods, relations between different applications, and their suitable technology options. One of the authors (Dr. Takashi Ohsawa) is known as the inventor of FBC and presented the award-winning paper at the IEEE International Solid-State Circuits Conference (ISSCC) in 2002 for the cell concept and a memory design using the cell.