Millisecond pulse electrical heating allows studying such thermophysical properties of materials as specific enthalpy, heat capacity, heat and temperature of melting, electrical conductivity, density and emissivity. Materials under study include various refractory metals, carbides, graphite, and any high-temperature conductive material. The temperature range for this technique covers high-temperature solid and liquid states of matter. Temperature diagnostic for this experimental technique can be performed by single, two- or multiwavelength optical pyrometry. The main problem of such diagnostic consists in unknown spectral emissivity of the material under study; different solutions to this problem are possible.