A thermal type flow sensor for measuring a flow rate of a fluid, comprising: a sensor element formed on a semiconductor substrate, and a driver circuit for driving the sensor element, wherein the sensor element comprises a bridge circuit including a plurality of temperature sensitive resistive elements (7, 8, 9, 10) being made of a material that changes the resistance according to the temperature, the bridge circuit being formed in that a first series circuit comprising a first temperature sensitive resistive element and a second temperature sensitive resistive element is connected in parallel to a second series circuit comprising a third temperature sensitive resistive element and a fourth temperature sensitive resistive element; characterized in that the sensor element further comprises a resistor provided in the second series circuit between the third and fourth temperature sensitive resistive elements (9, 10) and adjusting the bride balance; the driver circuit comprises a differential amplifier circuit to which an intermediate voltage signal from between the first and second temperature sensitive resistive elements (7, 8) is inputted via a first wiring portion and to which an intermediate voltage signal from between the third and fourth temperature sensitive resistive elements (9, 10) is inputted via a second wiring portion, wherein two buffers (50, 51) are provided on the second wiring portion being electrically connected to the third and fourth temperature sensitive resistive elements (9, 10) and the differential amplifier circuit such that the buffers (50, 51) are configured to sense the voltage across the resistor; the driver circuit further comprises a multi-stage series resistor, a switch having plural switching elements for variably adjusting the voltage divided ratio of the multi-stage series resistor, a switch control circuit for controlling the switch, and a transistor being connected to a connection point between the first temperature sensitive resistive element and the third temperature sensitive resistive element; the multi-stage series resistor is provided on the second wiring portion electrically connected between the buffers (50, 51) and the differential amplifier circuit; and an output of the differential amplifier circuit is the base voltage of the transistor. a sensor element formed on a semiconductor substrate, and a driver circuit for driving the sensor element, wherein the sensor element comprises a bridge circuit including a plurality of temperature sensitive resistive elements (7, 8, 9, 10) being made of a material that changes the resistance according to the temperature, the bridge circuit being formed in that a first series circuit comprising a first temperature sensitive resistive element and a second temperature sensitive resistive element is connected in parallel to a second series circuit comprising a third temperature sensitive resistive element and a fourth temperature sensitive resistive element; characterized in that the sensor element further comprises a resistor provided in the second series circuit between the third and fourth temperature sensitive resistive elements (9, 10) and adjusting the bride balance; the driver circuit comprises a differential amplifier circuit to which an intermediate voltage signal from between the first and second temperature sensitive resistive elements (7, 8) is inputted via a first wiring portion and to which an intermediate voltage signal from between the third and fourth temperature sensitive resistive elements (9, 10) is inputted via a second wiring portion, wherein two buffers (50, 51) are provided on the second wiring portion being electrically connected to the third and fourth temperature sensitive resistive elements (9, 10) and the differential amplifier circuit such that the buffers (50, 51) are configured to sense the voltage across the resistor; the driver circuit further comprises a multi-stage series resistor, a switch having plural switching elements for variably adjusting the voltage divided ratio of the multi-stage series resistor, a switch control circuit for controlling the switch, and a transistor being connected to a connection point between the first temperature sensitive resistive element and the third temperature sensitive resistive element; the multi-stage series resistor is provided on the second wiring portion electrically connected between the buffers (50, 51) and the differential amplifier circuit; and an output of the differential amplifier circuit is the base voltage of the transistor.