This book intends to explore the atmospheric issue from an independent, architectural perspective. It is composed of two main sections. The first one introduces and analyzes the atmospheric concept inside the lexical scope of the architectural discipline, mapping the whole taxonomy of semantic declinations that are recognized by architecture, in addition to retracing the etymology of the term 'atmosphere' and its evolution. The second section studies the topic throughout the sensory-emotional filter of the perceiving subject located in the built environment, gleaning suggestions from neuroscientific knowledge. More recently, architecture and neuroscience have started to interact, both in the combination of their theories and through experiment-based investigations.