A thermal processing furnace comprises: a tubular heat insulation member 4 surrounding a processing vessel 3 for receiving and thermally processing an object to be processed w; a heating resistor 5 helically arranged on an inner circumferential surface of the heat insulation member 4; and a support member 13 disposed on the inner circumferential surface of the heat insulation member 4, the support member 13 supporting the heating resistor 5 such that the heating resistor 5 can be thermally expanded and thermally shrunk. The thermal processing furnace further comprises: a movement prevention member 15 disposed on the heating resistor 5 to be in contact with one side surface of the support member 13 so as to prevent a downward movement of the heating resistor 5.