The present invention is a semiconductor device including: a resistor R11 (first resistor part) and an FET 15 (second resistor part) connected in series between a power supply Vcc (first power supply) and ground (second power supply); an output node N11 provided between the resistor R11 and FET 15 and used for outputting a reference voltage; a feedback node N12 provided between the power supply Vcc and the ground; and a voltage control circuit (19) that maintains a voltage of the feedback node N12 at a constant level by using the reference voltage of the output node N11 and the voltage of the feedback node N12. The present invention can provide a semiconductor device having a reference voltage generating circuit capable of generating the reference voltage that does not greatly depend on a power supply voltage and its control method.