A voltage generating circuit that generates a comparison reference voltage having temperature characteristics proportional to output temperature characteristics of a current detecting element (q1, q2) by resistance-dividing a predetermined power supply voltage, the voltage generating circuit comprising: a first resistance voltage dividing circuit, configured by low temperature coefficient resistors whose resistance temperature coefficient can be taken to be practically zero being connected in series, that generates a reference voltage by resistance-dividing the power supply voltage; a plurality of second resistance voltage dividing circuits (12a, 12b), each configured by a resistor (HR, NR) having a positive or negative resistance temperature coefficient and the low temperature coefficient resistor being connected in series, that generates a temperature-dependent divided voltage by resistance-dividing the power supply voltage; an instrumentation amplifier that generates the comparison reference voltage in accordance with a difference between the reference voltage and the divided voltage; and a comparator that, when the divided voltage exceeds a predetermined voltage threshold in accompaniment to a temperature rise, changes the divided voltage generated by the second resistance voltage dividing circuit (12a, 12b) and applied to the instrumentation amplifier, wherein the second resistance voltage dividing circuit (12a, 12b) generates a plurality of divided voltages of differing temperature gradients, and the comparator selects a divided voltage with a small temperature gradient from the plurality of divided voltages at a time of normal temperature and applies the selected divided voltage to the instrumentation amplifier, and when the divided voltage with the small temperature gradient exceeds a predetermined voltage threshold, the comparator selects a divided voltage with a large temperature gradient and applies the selected divided voltage to the instrumentation amplifier. a first resistance voltage dividing circuit, configured by low temperature coefficient resistors whose resistance temperature coefficient can be taken to be practically zero being connected in series, that generates a reference voltage by resistance-dividing the power supply voltage; a plurality of second resistance voltage dividing circuits (12a, 12b), each configured by a resistor (HR, NR) having a positive or negative resistance temperature coefficient and the low temperature coefficient resistor being connected in series, that generates a temperature-dependent divided voltage by resistance-dividing the power supply voltage; an instrumentation amplifier that generates the comparison reference voltage in accordance with a difference between the reference voltage and the divided voltage; and a comparator that, when the divided voltage exceeds a predetermined voltage threshold in accompaniment to a temperature rise, changes the divided voltage generated by the second resistance voltage dividing circuit (12a, 12b) and applied to the instrumentation amplifier, wherein the second resistance voltage dividing circuit (12a, 12b) generates a plurality of divided voltages of differing temperature gradients, and the comparator selects a divided voltage with a small temperature gradient from the plurality of divided voltages at a time of normal temperature and applies the selected divided voltage to the instrumentation amplifier, and when the divided voltage with the small temperature gradient exceeds a predetermined voltage threshold, the comparator selects a divided voltage with a large temperature gradient and applies the selected divided voltage to the instrumentation amplifier.