The machine is used to study and determine thermal conductivity coefficient of various materials. A test piece with certain dimension and thickness (300 x 300mm, thickness 50, 75, 100mm) as per standard is tested in contact with cold and hot surfaces with constant temperatures. Due to the difference in temperature of the specimen surface, a heat flux perpendicular to the specimen surface is created which is calculated by the machine, then the thermal conductivity coefficient is derived subsequently. Two flux sensors are mounted on the top and bottom of the specimen to measure the exact heat flux. The working temperature at the lower surface is 50ºC, 100ºC, but at the upper surface is -5ºC and -10ºC; the temperature separation degree for upper and lower sheets is 0.1ºC. The lower surface is heated by a heater and the upper one is cooled down by thermo electric modules with specific fans. The controllers used for hot and cold surfaces are of PID type. Another advantage of the machine is displaying heat, heat fluxes, as well as drawing thermal conductivity coefficient (K) over time by computer which facilitates the its application.