| abstract |
(57) [Problem] To provide a flow sensor having a thin film structure, Suppresses etching of the thin film structure due to foreign matter in the external environment. SOLUTION: The thin film structure portion 2 provided on a hollow portion 6 of a substrate 1, a heater 3 and a temperature measuring member 5 formed in the thin film structure portion 2, one end of which is electrically connected to the heater 3 and the temperature measuring member 5. And the other end side is drawn out to a portion other than the thin film structure portion 2 of the substrate 1, and a lead portion 7 is formed, In the flow sensor which measures the flow rate of the fluid based on the temperature change of the temperature measuring element 5 due to the flow of the fluid while heating the heater 3, one end of the lead portion 7 has a longitudinal direction that is a thin film structure portion. The shape is such that it becomes the normal direction of the isotherm of the temperature distribution generated in FIG. |