Patent ID: 7886594

Claim:
A thermal-type fluid flow sensor, comprising: a heating resistive element; a first temperature-measuring resistive element for detecting a temperature of the heating resistive element; a second temperature-measuring resistive element for detecting the temperature of air on an upstream side of air heated by the heating resistive element; a third temperature-measuring resistive element for detecting the temperature of air on a downstream side of air heated by the heating resistive element, and a fourth temperature-measuring resistive element for detecting the temperature of air, wherein the heating resistive element, and the first, second, third and fourth temperature-measuring resistive elements are formed on a substrate, wherein the heating resistive element is disposed in an upper layer or a lower layer of the first temperature-measuring resistive element, and wherein a resistance ratio of materials of the heating resistive element is larger than a resistance ratio of materials of the first temperature-measuring resistive element.