Provided in one disclosure of the present specification is a method for a wireless device attempting network access. The method may comprise the steps of: an RRC layer of the wireless device receiving, from a cell, a first piece of information relating to an NB-IoT RAT; the RRC layer receiving, from the cell, a second piece of information indicating whether to block access to exception data; the RRC layer obtaining, from an upper layer, an RRC establishment cause set as outgoing exception data, when an NAS signaling process is initiated to transmit the exception data; and performing an access block inspection.