The present disclosure relates to a 5G or pre-5G communication system for supporting a data transmission rate higher than that of a 4G communication system such as LTE. According to one embodiment of the present invention, a method in a roaming environment supporting a network slice is provided. The method comprises the steps of: receiving, from a terminal, a first packet data unit (PDU) session request message including slice assistance information indicating the properties of a service the terminal intends to use; transmitting, to a network function (NF) repository function, a first discovery request message including a home public land mobile network (PLMN) ID of the terminal and the slice assistance information; and receiving, from the NF repository function, a first discovery response message including a session management network function (SM NF) address of the home PLMN. The SM NF is selected on the basis of the slice assistance information.