This paper presents an analysis and investigation of the effect thermal anealing treatment on structural and electrical properties of micro heater conductor. Conventional micro fabrication process has given a higher resistance impact on the heater conductor properties. Higher conductor resistance obtains higher source for micro heater to be operated. Since the micro heater is used for micron-sized devices, only small amount of source is consumed for the micro component. Therefore annealing process is necessary to reduce the resistance of metal conductor heater. In this work, the thermal annealing treatment process was carried out in nitrogen atmosphere at temperature of 450°C for 30 minutes. Structural properties were studied using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) while an electrical property was investigated using heater characterization measurement and testing. The analysis shows that thermal annealing treatment improved the electrical properties of the heater conductor element and provided some changes in samples, such as the grain size increment or the decrease of the strain.