Over the last few years the use of maps as a tool for decision processes has increased, as well as computational capabilities that allow creation of several kinds of visualization and many different ways of data integration. The proposition of an Electronic Atlas is inserted at this context, as an aid for decision making process at social assistance field. This book provides a conceptual point of view about map design and map use, emphasizing issues concerning to interactivity. It addresses Electronic Atlas concept and functionalities, and presents an analysis about available products, notably concerning interface and functionality topics. Also it is introduced an Electronic Atlas modeling and implementation procedure, referring to data of Parana state councils, in the south region of Brazil. This Atlas was evaluated by its users and results made possible to assure the importance of this kind of instrument for spatial analysis. This book can be useful for professionals that work with digital atlases, and for cartography and GIS software analysts.