Plasma as the fourth state of matter is an ionized gas consisting of both negative and positive ions, electrons, neutral atoms, radicals, and photons. In the last few decades, atmospheric-pressure plasmas have started to attract increasing attention from both scientists and industry due to a variety of potential applications. Because of increasing interest in the topic, the focus of this book is on providing engineers and scientists with a fundamental understanding of the physical and chemical properties of different atmospheric-pressure plasmas via plasma diagnostic techniques and their applications. The book has been organized into two parts. Part I focuses on the latest achievements in advanced diagnostics of different atmospheric-pressure plasmas. Part II deals with applications of different atmospheric-pressure plasmas.