Disclosed are a method whereby user equipment operates in a wireless communication system, and a device for supporting same. Disclosed more particularly are: a method whereby, in case a base station which operates multiple analogue beams is connected to user equipment, the user equipment determines a cell-level radio link failure (RLF) and a beam-level RLF through signal transmission and reception to and from the base station and carries out an operation based on the determination; and a device for supporting said method.