A tensile-testing system that allows tests at elevated temperature was developed. Using this system, we evaluated the mechanical properties of micro-scale single-crystal silicon film at 573 K. The silicon test specimens had a surface orientation of (100), and a tensile direction of <110>. The average measured Young's modulus and fracture stress were 144 GPa and 5.19 GPa, respectively, at 573 K. At room temperature, Young's modulus and fracture stress were 137 GPa and 4.89 GPa. These similar values show that the mechanical properties of single-crystal silicon film hardly change at 573 K compared to room temperature.