Data transfer apparatus and data transfer method

A data transfer apparatus comprising:

• a transfer portion that reads out image data associated with identification information and stored in a first storage medium, and transfers the image data to a second storage medium;
• an identification portion that identifies, by means of the identification information, image data associated with the identification information and stored in the first storage medium, and image data associated with the identification information and stored in the second storage medium;
• a specification portion that, when transfer of image data by the transfer portion is terminated partway, determines the presence or absence of untransferred image data to the second storage medium among image data having the same identification information as each other, based on the identification result by the identification portion, and that, when the presence of untransferred image data is determined, specifies, as image data related to the untransferred image data, image data having the same identification information as the untransferred image data among the image data stored in the second storage medium;
• and
• a deletion portion that deletes the image data specified by the specification portion from the second storage medium.