To solve the problems that, conventionally, as a waste tire carbonization system, a char production method with a combustion tower and a rotary kiln has been often adopted, but, in the conventional method, the refining of highly coupled char has been caused, the physical pulverization of hard matter is extremely difficult, and further, even if expensive equipment has been used in an explosion method, an arc contact discharge method or the like on nanocarbon production, a refined amount has been minute and, the methods have been dangerous.

By sealing a squeezed gaseous nitrogen into a waste tire combustion carbonization furnace under suitable conditions, the refining of char in a foamed state is made possible, most suitable physical properties can be obtained as those of pulverization type nanocarbon refining raw materials, pulverization by a general pulverizer is facilitated, and a large quantity of nanoparticles can be produced. Further, the electrostatic adsorption system where foamed char properties are made the most of, and an electrostatic plate is provided, so as to perform adsorption refining is low-cost and has selectivity and safety, and solves various problems regarding nanocarbon production.