The inventive concept relates to a thermal conductivity measuring device. The thermal conductivity measuring device may include a first structure which is connected to one side end of a sample and receives heat from a heat source; a second structure connected to the other side end of the sample; a first stage connected to the first structure while supporting the first structure; a second stage connected to the second structure while supporting the second structure; a connection unit connected between the first stage and the second stage; and a measuring unit measuring temperatures of the first and second structures and the first and second stages. Since the thermal conductivity measuring of the inventive concept correct a temperature change of a stage due to heat transmission emitted from the stage considering a measurement environment, reliability of measurement may be improved.