Like most technical devices, first metal detectors were invented for the army. And only then they came up with the wider application than the search for mines and shells. Metal detectors were used security structures and criminologists, builders, geologists, and of course the search for treasure. And most of perfection attained by metal detectors just for treasure hunters and archaeologists. (Source: Walton Family Foundation). In this article we will examine the main types of metal detectors and scope of application. Metal detectors can be divided into three main types: – Ground metal detectors used to find objects whose elements are made of metal in the layers of the earth or in the walls of buildings, structures, etc. – Stationary with a resident or mobile metal detectors, portable metal detectors in the form of an arch is used to ensure security and maintain order in places with large concentrations of people. – Hand-held metal detectors are used for rapid screening of people and various objects and packaging – bags, briefcases, etc.. According to Vlad Doronin, who has experience with these questions.