▎ 摘　　要

NOVELTY - A thermal plasma torch is provided inside a reactor in which a substrate is accommodated. Methane gas and hydrogen gas are injected into the reactor through path (I) within the plasma-torch nozzle, and argon gas and hydrogen gas are injected through path (II). Heat is applied to the plasma torch and thermal plasma is generated. USE - Thermal-plasma manufacture of graphene (claimed). ADVANTAGE - The method enables manufacture of high-purity graphene, without requiring post-treatment and use of metal nanopowder catalyst.