An anti-static floor mat or ground mat is an anti-static device that safeguards an individual or piece of equipment like a PC from an electrostatic discharge (ESD). Computer components that are sensitive to static electricity or ESD are motherboards, CPUs, expansion cards and memory devices.Antistatic mats are used under keyboards or mice and may also be placed on or under other equipment. They are particularly useful when working on computer components. Once an anti-static mat is grounded, it is important not to lift the component off the mat because it will be susceptible to ESD.