Spinel type ferrites are interesting materials due to their both magnetic and semiconductor properties. These materials are widely used and exploited already from the 40ties of the last century. Nowadays, the use of the ferrite materials grows and, continuing miniaturization trend in both electrical and biological engineering, there is a need to develop synthesis methods and to do characterization of the ferrite nanomaterials. Many books and review articles exist related to spinel ferrite materials properties and applications. In this book we focused on nanostructured spinel type ferrites, its properties, synthesis and applications.