The present invention relates to a wireless access system supporting an unlicensed band, and provides a method for configuring a transmission opportunity (TxOP) section, and devices for supporting the same. The method for configuring a transmission opportunity (TxOP) section in a wireless access system supporting carrier aggregation (CA) with an unlicensed band, in one embodiment of the present invention, comprises the steps of: receiving, by a terminal, TxOP start information for indicating the start of the TxOP section; receiving orthogonal frequency division multiplexing (OFDM) symbol position information for indicating an OFDM symbol starting data transmission and reception in the TxOP section; and transmitting and receiving the data in a subframe (SF) of an S cell indicated by the TxOP start information on the basis of the OFDM symbol position information.