To provide a heat processing tool such as a soldering iron, steam iron, hair iron, hot melter and the like which can be used within several seconds after switching on an electric source.

By using the electric source circuit which can greatly elevate the temperature of the processing parts by means of supplying the predetermined high electric power to the heater 2 during predetermined short time in every one operation of the switch 3 and which can maintain approximately that temperature by switching to the low electric power after that or when the switch 3 is not operated, and by using the more excellent heat conductors than the material quality of the heater in the heat conductivity such as aluminum nitride as the processing parts or as the electrical isolator in the metal processing parts, and then by making the metal plates of nickel-chrome alloy, etc., as thin as possible and uniformly narrow in width as the heater and adhering them closely to the conductors, one heat block can be generated immediately in every one operation of the switch and as a result, the temperature and the heat quantity of the processing parts can be raised in stages according to the number of times in the operations of the switch.