Disclosed is a reference voltage circuit which includes control means for exercising control so as to equalize a divided voltage that is output from a first current-to-voltage converting circuit having a diode-connected MOS transistor and voltage-dividing resistors and a divided voltage that is output from a second current-to-voltage converting circuit having a diode-connected MOS transistor and voltage-dividing resistors; a first current mirror circuit having a non-linear input/output characteristic for supplying currents to the first and second current-to-voltage converting circuits, respectively; a second current mirror circuit having a linear input/output characteristic for outputting a current proportional to the value of the current supplied to the first current-to-voltage converting circuit; and a third current mirror circuit having a linear input/output characteristic for outputting a current proportional to the value of the current supplied to the second current-to-voltage converting circuit. A third current-to-voltage converting circuit converts a current, which is the result of adding the output currents of the second and third current mirror circuits, to a voltage to supply the so converted voltage as a reference voltage.