The present specification provides a method for configuring a common search space (CSS) in a wireless communication system. Specifically, a method performed by a network may comprise the steps of: acquiring, from at least one terminal, information on a bandwidth of the at least one terminal; determining a particular subband indicating a bandwidth unit available for communication with the terminal; determining the number of particular subbands on the basis of the determined particular subband and the acquired information on the bandwidth of the terminal; and mapping, on the basis of the determined number of particular subbands and the aggregation level of the CSS, a part of the aggregation level to each particular subband. Therefore, it is possible to efficiently use radio resources through the CSS configuration method proposed in the present specification.