PURPOSE: To reduce the influence of a magnetic flux generated by a variation of a large current in a fixing heater or an exposing lamp, by placing in parallel at least two pieces of heaters or lamps, so that the directions of electric currents flowing to each other are opposed to each other.

CONSTITUTION: A fixing heater unit of a copying machine is provided with a heat roller 1 and a pressure roller 2 whose outside peripheral surfaces have been brought to sliding contact with each other, they are pivotally supported by body side plates 3, 4 so as to be rotatable, and on a hollow part of the heat roller 1, two pieces of fixing heaters 5, 6 are provided in parallel in the axis center direction. Also, these heaters 5, 6 are wired electrically so that directions of currents to be conducted electrically are opposed to each other. Magnetic fluxes generated by the currents flowing to the respective heaters 5, 6 are mutually cancelled as indicated by arrows θ1, θ2, the magnetic flux is reduced and noise is also reduced.