PROBLEM TO BE SOLVED: To provide a plasma heating device, capable of simply controlling the area and depth to which plasma heating treatment can be applied. SOLUTION: The plasma heating device 1A comprises a plurality of electrodes with nozzle 10A, 10B arranged in a direction getting closer to each other the closer it is to the tip part discharging plasma arcs Aa, Ab; A direct current power source 8A impressing direct current voltage between the electrodes of the electrode with nozzles, or between the electrodes with nozzle 10A, 10B and a substance to be heated 100, and discharging the plasma arcs Aa, Ab as flow channels of the direct current; and heating part control means 7, 20 for discharging a gas G to the area near to the part where the plasma arcs Aa, Ab are jointing with each other, and controlling the contact state of the plasma arcs Aa, Ab with the substance to be heated 100. COPYRIGHT: (C)2006,JPO&NCIPI