Muography is a term recently introduced to embrace different techniques that profit from the penetration capability of the muon component of cosmic rays to investigate the interior of large and otherwise inaccessible structures. Primary cosmic rays - high energy particles originating outside the solar system - interact with the Earth atmosphere and generate muons, particles with the same electric charge as the electron, while their mass is 200 times heavier. At the Earth's surface, cosmic muons represent the most abundant component of cosmic rays, and favourably, they can feature energies sufficiently high to penetrate even thick and dense materials, giving the opportunity of unveiling the internal structure of large volumes. Muography was made possible by the development of detectors in the field of particle physics, allowing the exploitation of this natural source for imaging in a vast variety of fields, characterizing this technique as truly interdisciplinary, and leading to significant advances in several disciplines. This book tries to cover all aspects of this methodology, with the different chapters pointing to the general physics principles, to the technological and image reconstruction challenges and to the principal applications in several fields, such as archaeology and geology but also civil and industrial applications. The volume contributors had omitted unnecessary technical details, while focusing on the main features and methodologies. Hence, the book not only targets scientists working in the field but also non-specialists, who might enjoy the reading as a tutorial.