The present invention relates to a wireless communication system and, more specifically, to a method and a device for scanning multiple bands in a wireless LAN system. The method by which a station (STA) scans in a wireless communication system, according to one embodiment of the present invention, comprises the steps of: transmitting a first frame to a first access point (AP); and receiving a second frame responding to the first frame from the first AP, wherein the first frame includes service set identifier (SSID) information and information on an operation class supported by the STA, and the second frame can include information for indicating whether or not to filter and information on a second AP.