Channel sounding method in wireless lan system and device for supporting same

Disclosed are a channel sounding method in a wireless LAN system and a device for performing the same. An access point for performing the channel sounding method includes information of a restricted access window for channel sounding in a beacon so as to broadcast the beacon, and can transmit null data packets (NDPs) for channel estimation within the restricted access window to a station. The station estimates channel information on the basis of the NDPs, and can transmit the estimated channel information to the access point.