According to Van der Pauw’s law, HET measures the electrical transport properties and main parameters of materials, such as carrier concentration, mobility, resistivity, Hall coefficient, etc. Thin film or thin layer materials can be measured, and it can be applied to all semiconductor materials. Including Si, ZnO, SiGe, SiC, GaAs, InGaAs, InP, GaN (N-type & P-type can be measured), widely used in domestic universities, research institutes, semiconductors, metals, high thermal conductivity organic new materials and other industries.