To facilitate manufacturing of a helical resistive heat-generating member composed of ceramic resistive heat generating member, and improve its productivity, quality and uniform temperature characteristic.

There is provided a heat treatment device 1 comprising a processing container 2 for storing treated items to perform a heat treatment for them, and a heater device 5 having a resistive heat-generating member 4 at an inner circumference of a cylindrical heat insulating material 3 enclosing a circumference of the processing container 2. The resistive heat-generating member 4 of the heater device 5 is formed such that either arcuate or one to several turns of a plurality of resistive heat generating composing pieces 4a having ceramic resistive heat generating member are connected to form a helical shape.