Photonics is a key technology of this century. The combination of photonics and Si technology is of great importance due to the potentiality of coupling electronics and optical functions on a single chip. This book describes different aspects of Silicon Nanophotonics, from fundamental issues to practical devices. The 2nd edition is essentially different from the book published in 2008. Eight chapters of the 1st edition are not included in the new edition because the recent progress on those topics has not been large enough. Instead, seven new topics appear, which describe recent achievements in the field.