A data migration system includes a migration source device and a migration target device that are capable of reading and writing data from and to an IC card. The migration source device includes a first storage section and a data write section. The first storage section stores user information. Upon detection of a waving of an IC card of a user, the data write section authenticates the user of the IC card and stores a user information piece about the authenticated user stored in the first storage section to the IC card. The migration target device includes a second storage section and a data receiving section. Upon detection of a waving of the IC card of the user, the data receiving section authenticates the user of the IC card and stores the user information piece stored in the IC card to the second storage section.