Abstract: There is disclosed a reference power supply apparatus comprising two resistors R1, R2 connected in series with each other between a reference level line, and a terminal to which a voltage having a predetermined level difference E from the reference level line is applied. Moreover, a division circuit is used to divide a voltage E between the opposite ends of two resistors R1, R2 by a voltage Vi between the opposite ends of the resistor R2, and a reference voltage Vo corresponding to a ratio of a resistance value of the resistor R1 to that of the resistor R2 is obtained.