Corrosion resistivity of a thermistor (2) is improved. Corrosion resistant material is used for lead wires (5A, B) of the thermistor, and an exposed portion of electrodes (3A, B) of the thermistor and a portion (6) surrounding a weld portion of the lead wires are coated with corrosion resistant material. Since the lead wires themselves are made of corrosion resistant material, there occurs no corrosion in the welding portion and a cut working portion. Further, since the lead wires and the exposed portion of the electrodes are coated with corrosion resistant material, it is possible to provide an electronic device having the extremely high corrosion resistivity and hence the high durability and reliability, with the result that the electronic device can be used for a long period without corrosion under the heavily corrosive environment, such as sulfur dioxide gas atmosphere.