Compensation wires for Pt/Pd thermocouple was manufactured using Cu/Ni alloys. Their thermoelectric voltage has been tested from room temperature to about 150℃. Alloys of Cu_(95.5) Ni_(4.5) and Cu_(89.5)Ni_(10.5) introduced only small emf differences to Pt/Pd thermocouples. indicating a real possibility of industrial use. Above 1000 ℃, the temperature difference was expected to he small as ±0.5 ℃, and the difference would be minimized by adjusting the Ni content with a small amount.