To reduce a frictional resistance between a supporting member and a resistance heating element when the resistance heating element thermally expands and contracts to prevent the occurrence of a permanent distortion caused by a residual stress of the resistance heating element so that a durability of the resistance heating element may be improved.

The heat processing furnace includes: a cylindrical heat-insulating material 4 that surrounds a processing chamber 3 for receiving and heat-treating an object to be processed w; a spiral resistance heating element 5 arranged along the inner circumferential surface of the heat-insulating material 4; a supporting member 13 for supporting the resistance heating element 5 in a given pitch, which is provided in the axial direction along the inner circumferential surface of the heat-insulating material 4; and a plurality of terminal plates 14 extending radially outward through the heat-insulating material 4, being disposed in appropriate periods in the axial direction outside the resistance heating element 5. In this heat processing furnace, the supporting member 13 comprises a plurality of pipe-shaped members 51 each with one end embedded into the heat-insulating material 4 and the other end protruded in the radially inward direction, the resistance heating element 5 is supported on the curved top surface portions of the pipe-shaped members 51, line-shaped members 55 are each bridged between tips of each vertically neighboring pipe-shaped members 51 to prevent the resistance heating element 5 from being dropped off, and both ends 55a of each line-shaped members 55, passed across the axial central holes of the vertically neighboring pipe-shaped members 51, are embedded in the heat-insulating material 4 and fixed there.