The present invention relates to a broadband wireless access system, and more particularly, to a method for a mobile station to save power for prescribed duration without performing a paging procedure and apparatus therefor. According to one embodiment of the present invention, a method of a DCR (deregistration with content retention) mode operation of a mobile station in a broadband wireless access system includes transmitting a first message including a first code indicating an entry request at the DCR mode to a base station, receiving a second message including a second code indicating whether to allow the entry request from the base station, and if the second code is set to a value indicating an allowance of the entry request, operating in the DCR mode while a preset timer is valid.