Hot-film shear stress sensor is one of fluid measurement technologies making up MEMS (Micro Electro Mechanical System). In order to understand properties of hot film shear stress sensors, numerical analyses were carried out. From the results for CTA (Constant Temperature Anemometer), the relationship between Reynolds number and Nusselt number which is based on heat transfer to fluid was conducted. Nusselt number was affected of not heat conductivity but thermal diffusivity of the material under the heater. Furthermore, the fluctuation of shear stress was caused by the clearance between sensor and wall.
