PURPOSE: To provide a heater designed to permit the appropriate temperature control, etc., without generating noise in conductor wiring.

CONSTITUTION: In a heater H which comprises a longitudinal strip of resistance heating element 2 formed on one side of a substrate 1 and two streaks of wiring conductors 51, 52 on the other side of the substrate 1, for connection to a temperature detecting element 6 for detecting the temperature of the heating element 2, the two streaks of wiring conductors 51, 52 are formed in equally spaced positions on both sides of the resistance heating element 2 and in the direction of extension of the heating element 2; and a method for passing current to be carried by the heater H, a fixing device using the heater H, and equipment having the fixing device built in are described. A precise signal can be fed back to a control circuit using simple constitution without providing electrical noise to the connecting wire of the detecting element, and so precise control of temperature and the like can be made within a predetermined range, producing the effects of quality enhancement in any products that use the heater, and safety enhancement in the equipment.