This book introduces the MagLev testing method for density measurement and density-based applications of diamagnetic and low-magnetic objects using permanent magnets. The book surveys the most relevant papers on the theory and model of various MagLev methods that have become the foundation to elucidate the principles of MagLev and the conditions for stable levitation. A thorough summary of the improvements demonstrates the applications and potential of the MagLev method in many fields. This book is separated into 11 chapters to present MagLev testing method fully, including a review of the background of MagLev, theories and basic principles of the stable levitation of object, different dimensions of applications of MagLev in the fields of mechanical engineering, chemistry, and bioengineering, and sophisticated applications of manipulation and separation. This book would benefit the audience in the field of mechanical engineering, chemistry, materials science,and bioengineering, since magnetic levitation method has proved itself suitable for the density-based analysis and applications of materials of different scales. The analysis in this book will help the audience deeply understand the mechanism of magnetic levitation, and it can serve as an instruction for the magnetic levitation procedure, or guidebook for the magnetic levitation setup. With the viewpoints and thoughts about MagLev running through this book, this book may spark the audience's interest towards magnetic levitation method, and enlighten them to further develop Maglev method.