The present invention provides a migration apparatus that realizes safe migration of secret data between a first terminal device and a second terminal device. Before transmitting the secret data to the second terminal device, the migration apparatus (i) receives, from the first terminal device, a minimum evaluation level required of a destination of the secret data by the first terminal device, (ii) receives, from the second terminal device, an evaluation level of the second terminal device, (iii) judges whether the evaluation level of the second terminal device is lower than the minimum evaluation level, and (iv) sends the secret data to the second terminal device only if the evaluation level of the second terminal device is no lower than the minimum evaluation level.