To obtain a copied image which is appropriately and regularly finished from plural images to be exposed with the same exposure amount at a high yield.

Information recorded on the magnetic recording part of a negative film is read (200), and in the case of judging that plural negative images to be exposed with the same exposure amount are present in the negative film based on the read information (yes, 212), specified negative images estimated that high accuracy in the exposure calculation may be obtained are selected as the negative images used for the calculation of the common exposure amount among plural negative images (216), then, the individual exposure amount of the selected specified negative images is calculated (218), the mean value of the individual exposure amount of the specified negative images is calculated as the common exposure amount (220). The negative images to be exposure with the same exposure amount are respectively exposed on a photographic printing paper with the common exposure amount.