A heat-processing furnace comprises: a processing vessel for housing an object to be processed to thermally heat the object to be processed; a cylindrical heat insulating member surrounding the processing vessel; a helical heating resistor disposed along an inner circumferential surface of the heat insulating member; and support members axially disposed on the inner circumferential surface of the heat insulating member, for supporting the heating resistor at predetermined pitches. A plurality of terminal plates are disposed outside the heating resistor at suitable intervals therebetween and attached to the heating resistor, the terminal plates radially passing through the heat insulating member to be extended outside. A plurality of fixing plates are disposed outside the heating resistor at suitable intervals therebetween and attached to the heating resistor, the fixing plates being fixed in the heat insulating member. The fixing plates are attached to the heating resistor by the same attachment structure as the attachment structure of the terminal plates to the heating resistor.