demand for flow sensors capable of reliable operation in high-temperature environments is escalating across various sectors, including automotive, aerospace, oil exploration, and power electronics. Assessing the performance of flow sensors under such complex conditions is crucial, yet high-temperature micro-electromechanical systems (MEMS) flow sensors are exceedingly scarce. This study focuses on the performance evaluation of a MEMS flow sensor designed for high-temperature applications. Performance assessment is primarily based on two parameters: the change in resistance (AR) and the degradation of the Seebeck coefficient. To achieve this, a storage life test was conducted at temperatures of 120 degrees C, 150 degrees C, and 180 degrees C. The resistance changes of both the microheater (HEATER) and the sensing structure (UP/DOWN) are discussed. In addition, the study documents a decrease in the Seebeck coefficient as temperature increases. The lifetime of the high-temperature MEMS flow sensor was determined through these experiments. Results demonstrate the samples' exceptional repeatability and consistency following exposure to high temperatures. Thus, this research not only sheds light on the behavior of MEMS flow sensors in high-temperature settings but also significantly enhances the accuracy of reliability analyses. Filling a crucial knowledge gap in the reliability study of MEMS flow sensors, this work offers valuable insights for the design, fabrication, and application of these devices.