1. A migration apparatus which is used in a mobile environment, the apparatus comprising: a memory to store target software; a policy manager configured to select an order of basic copying, duplicate copying, and control transfer from a combination thereof as a migration method for the target software according to a current migration environment, wherein the current migration environment comprises at least one of a state of a source device, a state of a target device, and a state of a network connecting the source device and the target device; and a migration manager configured to perform migration of the target software according to the selected migration method, wherein the basic copying comprises copying one or more images of the target software to the target device, the duplicate copying comprises making a software environment of the target device nearly identical to a software environment of the source device, and the control transfer allows a user who has used the source device to use the target device.