An electronic apparatus and a firmware update method thereof are provided. The electronic apparatus includes a firmware storage device, a microcontroller and a network interface module. Firmware is stored in the firmware storage device, and the microcontroller is coupled to the firmware storage device. The network interface module is coupled to the microcontroller, receives a packet from a remote server via a network, and determines whether the packet conforms to a specific format by determining whether the packet is a Wake-on-LAN packet and whether the packet includes a firmware update command. If the packet conforms to the specific format, the microcontroller obtains firmware update data provided by the remote server through the network interface module, to refresh the firmware stored in the firmware storage device by using the firmware update data.