Weak magnetic field sensors have always been an area of great interest due to its immense potential applications in a wide array of fields such as magnetic anomaly detectors (MAD) in defense related industry or bio-magnetic field sensors in biomedical industry.The performance of such sensors greatly depends on the magnetic softness of the sensing elements.Thus, optimization of the post-heat treatment process is crucial as it serves to release stresses induced during the deposition process.In this study, furnace annealing was carried out on NiFe/Cu composite wires at a range of annealing temperatures from 210℃-1050℃.