A thermal flow meter comprising: a subsidiary passage having an opening portion through which a fluid to be measured is to be drawn in; and a sensor element disposed in the subsidiary passage, the sensor element for measuring a flow rate of the fluid to be measured, wherein the sensor element includes: a semiconductor substrate; an electrically insulating film formed on the semiconductor substrate; a cavity portion formed in the semiconductor substrate; a heating resistor formed on the cavity portion via the electrically insulating film; a heating temperature sensor for detecting heating temperature of the heating resistor; a driving circuit for controlling the heating temperature of the heating resistor using the temperature detected by the heating temperature sensor; a wiring portion (30i, 30j) connected electrically to the heating resistor; and a wiring portion (33a, 33b) for leading electrically from the heating temperature sensor to an outside of the cavity portion wherein the heating resistor and the wiring portion (30i, 30j) have a connecting portion for connecting therebetween, the connecting portion including a throttle portion; and wherein the heating temperature sensor is disposed along the throttle portion so as to surround a periphery of the heating resistor, characterized in that, the wiring portion (33a, 33b) connecting the heating temperature sensor has a wire width on the cavity portion wider than a wire width of the heating temperature sensor; the throttle portion comprises two recesses (38a, 38b) formed by the heating resistor and the wiring portion (30i, 30j) connecting the heating resistor; and the heating temperature sensor is disposed along the shape of the recesses (38a, 38b). a subsidiary passage having an opening portion through which a fluid to be measured is to be drawn in; and a sensor element disposed in the subsidiary passage, the sensor element for measuring a flow rate of the fluid to be measured, wherein the sensor element includes: a semiconductor substrate; an electrically insulating film formed on the semiconductor substrate; a cavity portion formed in the semiconductor substrate; a heating resistor formed on the cavity portion via the electrically insulating film; a heating temperature sensor for detecting heating temperature of the heating resistor; a driving circuit for controlling the heating temperature of the heating resistor using the temperature detected by the heating temperature sensor; a wiring portion (30i, 30j) connected electrically to the heating resistor; and a wiring portion (33a, 33b) for leading electrically from the heating temperature sensor to an outside of the cavity portion a semiconductor substrate; an electrically insulating film formed on the semiconductor substrate; a cavity portion formed in the semiconductor substrate; a heating resistor formed on the cavity portion via the electrically insulating film; a heating temperature sensor for detecting heating temperature of the heating resistor; a driving circuit for controlling the heating temperature of the heating resistor using the temperature detected by the heating temperature sensor; a wiring portion (30i, 30j) connected electrically to the heating resistor; and a wiring portion (33a, 33b) for leading electrically from the heating temperature sensor to an outside of the cavity portion wherein the heating resistor and the wiring portion (30i, 30j) have a connecting portion for connecting therebetween, the connecting portion including a throttle portion; and wherein the heating temperature sensor is disposed along the throttle portion so as to surround a periphery of the heating resistor, characterized in that, the wiring portion (33a, 33b) connecting the heating temperature sensor has a wire width on the cavity portion wider than a wire width of the heating temperature sensor; the throttle portion comprises two recesses (38a, 38b) formed by the heating resistor and the wiring portion (30i, 30j) connecting the heating resistor; and the heating temperature sensor is disposed along the shape of the recesses (38a, 38b).