A method, performed by a base station (BS), of indicating a channel occupancy time of an unlicensed band is provided and includes transmitting physical downlink control channel (PDCCH) configuration information to a user equipment (UE), performing a channel access procedure to occupy a channel of the unlicensed band, and transmitting slot format indicator information about at least one slot within a channel occupancy time occupied by performing the channel access procedure, based on the PDCCH configuration information, wherein the slot format indicator information is determined based on at least one of a maximum channel occupancy time of the BS or the channel occupancy time occupied by performing the channel access procedure.