The present invention discloses a plasma dry reforming apparatus for producing synthetic gas, main components of which are hydrogen and carbon monoxide, by reforming methane and carbon dioxide injected in plasma, the apparatus comprising: a plasma reformer 100, 200 which produces carbon dioxide plasma by making carbon dioxide supplied therein into plasma, ignites plasma flame by supplying hydrocarbon to the produced dioxide plasma, and produces synthetic gas by supplying methane to the plasma flame.