To provide an electrode structure for a plasma melting furnace in which oxidation consumption rate is small, and contact resistance against a bus-bar hardly changes for a long time.

As for the plasma melting furnace in which treated objects are melted by plasma arc, this is the electrode structure of the negative electrode connected to the bus-bar, and the negative electrode is formed of isotropic graphite, and an expanded graphite sheet is interposed between the isotropic graphite and the bus-bar.