A method for waking a device from a power save mode to an active mode includes: transmitting, by a first device, a magic packet through a predetermined channel to a second device, which operates in the power save mode by repeating a doze state and an awake state according to a predetermined period of time, for notifying the second device to switch to the active mode; and retransmitting the magic packet to the second device through the predetermined channel if a response to the magic packet has not been received from the second device and a predetermined time has not elapsed after transmitting the magic packet through the predetermined channel.