The present invention relates to a broadband wireless access system, and more particularly, to a method for efficiently operating a service unavailable mode of femto base station. The method for operating a service unavailable mode of femto base station in the broadband wireless access system according to one embodiment of the present invention, comprises the steps of: determining whether the preset condition for the operation of a service unavailable mode is satisfied; and broadcasting service unavailable mode information for indicating the state of service unavailable mode of the femto base station in accordance with the result of determination on the preset condition.