Patent ID: 7992435

Claim:
A thermal air flow meter, comprising: a semiconductor substrate; an electrical insulating film formed on the semiconductor substrate; and a heating resistor and a resistance temperature detector formed on the electrical insulating film, wherein the semiconductor substrate is partially removed to form a cavity in a region of the semiconductor substrate where bodies of the heating resistor and resistance temperature detector are formed, and thus the region having the heating resistor body and the resistance temperature detector body formed therein is formed into a diaphragm section, a protective film is formed on and outside a peripheral part of the diaphragm section, and is not formed in a region of the diaphragm section where the heating resistor body and the resistance temperature detector body are formed, and at a place where a heating resistor wire connected to the heating resistor body or a resistance temperature detector wire connected to the resistance temperature detector body crosses the peripheral part of the diaphragm section, a film component protruding from the electrical insulating film is arranged side by side with the heating resistor wire or with the resistance temperature detector wire.