An electronic device and a method for starting up the same, wherein the electronic device includes a firmware control unit, a power supply state storage unit, a basic input output unit, and an Ethernet interface coupled to power supply apparatus to a Power over Ethernet to receive a power supply via a network cable. The firmware control unit determines whether the power supply state of the power supply is in a first power mode, by checking a power supply state signal. When the power supply state is not in the first power mode, the basic input output unit executes a second power booting program. The firmware control unit communicates with the power supply apparatus via a network, increases the rated power of the power supply, sets the power supply state signal for controlling the power supply state to be in the first power mode, and restarts the electronic device.