Provided is a power supply circuit generating a desired voltage by voltage multiplication, and satisfying both a demand to reduce current consumption and a demand to enable operation with a low power voltage at the same time. A power supply circuit of the present invention includes: a voltage generating circuit for generating internal voltages VI1 and VI2 from a power supply voltage VDD; a voltage step-up/down circuit for generating voltages VO1 to VO3 each having a different level by multiplying the internal voltages VI1 and VI12; and a voltage comparison circuit for comparing the voltage VO2 with the power supply voltage VDD. The voltage generating circuit is configured to select one of the internal voltages VI1 and VI2 according to an output of the voltage comparison circuit. Additionally, a voltage multiplication rate of the voltage multiplication circuit is switched according to the output of the voltage comparison circuit.