Abstract: an electric arc heating system for use with a vacuum metallurgic unit, which includes at least one graphite electrode that is composed of two or more interconnected graphite electrode sections and is adapted selectively to be lifted and lowered by lifting and lowering means from which it can easily be disconnected, while the electrode or electrodes is or are surrounded by a tubular mantle and the latter is surrounded by jacket means in a vacuum-tight manner which jacket means has that end thereof which is remote from the metallurgic unit provided with closure means for tightly closing an opening at the last mentioned end.