The present invention relates to a method and apparatus for producing a nanoscale material having a graphene structure. The present invention provides a method and apparatus which compulsorily introduces graphite sulfuric acid slurry and a permanganate sulfuric acid solution into a microchannel, to cause an oxidation reaction among layers of graphite, and which in particular involves applying ultrasonic waves during the reaction in the microchannel to improve expansion and delamination efficiency among layers of graphite, injecting an aqueous hydrogen peroxide solution into a reaction termination portion to terminate the oxidation reaction, and cleaning and drying the thus-obtained reaction mixture to produce graphite oxide. The present invention also provides a method and apparatus which involve supplying the thus-produced graphite oxide into a fluidized bed furnace to produce a nanoscale material having a graphene structure through delamination caused by thermal shock. According to the present invention, the risk of explosion is reduced during the production of graphite oxide, mass production of graphite oxide is enabled, and a nanoscale material having a graphene structure, physical properties equal to those of carbon nanotubes, and superior dispersibility is produced.