A slice management system (1) is a slice management system managing slices that are virtual networks generated on a network infrastructure, comprises a memory storing a priority list in which slices of connection destination candidates of a UE (2) are aligned in order of priority levels and, in a case in which a connection request for a slice from the UE (2) is acquired, determines a slice to which UE (2) is to be connected on the basis of the priority list stored in the memory.