This is the first book on Additive Manufacturing that provides an original theory for the entire subject. It is the culmination of a search for the root cause of manufacturing problems that occur in practice. The author finds a reason why there are only two types of layer arrangement for manufacturing products and divides fabrication problems in additive manufacturing into two types: solvable and unsolvable. This allows readers to anticipate/avoid difficulty in manufacturing, saving materials, time, and resources. In addition, this book: Introduces a method to divide layer arrangements in additive manufacturing Divides fabrication problems in AM into two types: solvable and unsolvable Written in the form of questions and concise answers, with clarifying diagrams and essential design guidelines Clarifies the basic concepts of layers in AM.