A stand-by power control device includes a power block unit that receives a driving power voltage and a non-driving power voltage from a power supply unit and that selectively provides the driving power voltage or the non-driving power voltage as a supply voltage, a stand-by power generation unit that receives the supply voltage and that outputs a stand-by voltage generated by reducing the supply voltage, a power selection unit that receives the supply voltage and the stand-by voltage and that selectively outputs the supply voltage or the stand-by voltage as an operating voltage, and a state detection unit that receives a state detection voltage from the power supply unit and that controls the power block unit, the stand-by power generation unit, and the power selection unit based on the state detection voltage.