Metal detector is a kind of instrument specially used to detect metal substances. Now metal detector can detect the kind of metal besides whether there is metal between objects or objects. In archaeology, metal detectors can be used to discover ancient tombs where metal objects are buried, and to uncover gold and silver treasures, jewelry, and various coins and ceramics.

Metal detectors themselves are legal, certified and licensed by the state, and metal detectors are not flammable, so it's OK to take buses, cars, high-speed trains, etc. But on the plane, because the power supply is battery, so if you take a plane, the instrument can be checked with the plane luggage, but the battery must be unloaded to carry the plane can not go luggage. So metal detectors can be brought on buses, cars, high-speed trains, etc. Airplanes are generally not allowed.