Traditional carbon materials such as graphite are currently extremely useful and have recently been applied to cutting-edge materials. However, it is a concern that as production will increase much more in the future, the impact on the environment during preparation will become a problem. Recently, we have succeeded in obtaining an extremely high orientation structure using a carbonization process in a strong magnetic field [“Magnetic orientation of hexagonal carbon layers at high temperature” Chem. Lett. 41, 1576 (2012)]. Because graphite has a two-dimensional structure in which graphene sheets are laminated, we expect that graphitization should be easily performed by using a precursor that originally has an oriented structure. When two types of precursors prepared in the absence and presence of a magnetic field of 6 T were graphitized under the same conditions, graphitization was promoted by 50 to 100 K for the precursor to which a strong magnetic field was applied. If we fabricate products with the same degree of graphitization, it is calculated that the graphitization energy can be suppressed by as much as 10% by using a magnetic field. Applying this technology to the preparation of graphite in industry is proposed to result in substantial energy savings.