With a foreword from G. Chapark, Nobel Prize Winner for Physics, this authored title gives a comprehensive description of modern gaseous detectors of photons and charged particles, a technology and devices widely used in physics experiments and industrial applications. In the last decade, a new generation of position-sensitive gaseous detectors has appeared: the micropattern gaseous detectors, which are now actively used in high-energy physics experiments and with very practical applications. The book will be useful to engineers, physicist, scientists, lecturers and students specialized in high energy physics, astrophysics, nuclear physics, medicine and radiation measurements in general.