The book “The Laser” consists of three chapters. The first chapter is devoted to the beginning of the scientific studies on metal vapor lasers in Bulgaria. The pre-history of laser research at the ISSP of BAS is described. Metal vapour lasers and their capabilities to cover the ultraviolet, visible and infrared spectral regions are analysed. The second chapter depicts the high-power copper bromide vapor laser: invention, scientific studies, industry – an example of successful innovation. The third chapter represents the introduction of the copper bromide vapor laser into industry in Bulgaria, Australia and the USA, as well as the international acknowledgement of the Bulgarian scientific and applied achievements in the field of metal vapor lasers.