An image processing apparatus being provided with: a volatile recording medium that stores image data; a nonvolatile recording medium that stores image data; a transfer portion that transfers image data page by page between the volatile recording medium and the nonvolatile recording medium; a controller that suspends transfer of one page of first image data, lets transfer of one page of second image data interrupt, and executes transfer of that page of the second image data on a priority basis, if a request to transfer that page of the second image data is issued with a higher priority level than that page of the first image data while that page of the first image data is being transferred by the transfer portion, and then, resumes transfer of an untransferred portion of that page of the first image data after that page of the second image data is completely transferred.