Provided are an apparatus and method of transmitting and receiving a wake-up signal. The method of receiving a wake-up signal includes the following: operating a radio frequency (RF) receiving unit that receives a wireless signal through an antenna during an SFD detecting time, wherein the SFD detecting time is shorter than a predetermined SFD detecting time period, according to the predetermined SFD detecting time period and detecting a start of frame delimiter (SFD) to indicate that the received wireless signal is a wake-up signal to wake-up a node in a sleep mode; and detecting the wake-up signal by continuously operating the RF receiving unit when the SFD is detected. Power consumption that is used to receive the wake-up signal can be reduced.