A method for transmitting/receiving data in an unlicensed band by a user equipment, UE, the method comprising: (S 1000) receiving configuration information comprising a parameter for configuring a plurality of resource block sets in the unlicensed band; (S 1010) checking the plurality of resource block sets based on the configuration information; receiving a result of a Listen Before Talk operation, called LBT operation, performed by the base station for each of the plurality of resource block sets; and (S 1020) transmitting/receiving data to and from a base station through at least one resource block set determined based on a result of the LBT operation, wherein each of the plurality of resource block sets are configured with a number of resource block determined based on the configuration information, wherein the configuration information comprises guard band configuration information for configuring at least one guard band in the unlicensed band, wherein the guard band configuration information comprises a starting common resource block of the at least one guard band and information to determine a number of resource blocks constituting the at least one guard band, wherein the at least one guard band is configured between the plurality of resource block sets so that each of the plurality of resource block sets is distinguished in the unlicensed band, characterized in that the guard band configuration information comprises subcarrier spacing information of a system bandwidth configured in the unlicensed band or subcarrier spacing information of a subcarrier spacing specific carrier bandwidth, the number of resource blocks constituting the at least one guard band is determined based on the subcarrier spacing information of the system bandwidth or the subcarrier spacing information of the subcarrier spacing specific carrier bandwidth. (S 1000) receiving configuration information comprising a parameter for configuring a plurality of resource block sets in the unlicensed band; (S 1010) checking the plurality of resource block sets based on the configuration information; receiving a result of a Listen Before Talk operation, called LBT operation, performed by the base station for each of the plurality of resource block sets; and (S 1020) transmitting/receiving data to and from a base station through at least one resource block set determined based on a result of the LBT operation, wherein each of the plurality of resource block sets are configured with a number of resource block determined based on the configuration information, wherein the configuration information comprises guard band configuration information for configuring at least one guard band in the unlicensed band, wherein the guard band configuration information comprises a starting common resource block of the at least one guard band and information to determine a number of resource blocks constituting the at least one guard band, wherein the at least one guard band is configured between the plurality of resource block sets so that each of the plurality of resource block sets is distinguished in the unlicensed band, characterized in that the guard band configuration information comprises subcarrier spacing information of a system bandwidth configured in the unlicensed band or subcarrier spacing information of a subcarrier spacing specific carrier bandwidth, the number of resource blocks constituting the at least one guard band is determined based on the subcarrier spacing information of the system bandwidth or the subcarrier spacing information of the subcarrier spacing specific carrier bandwidth.