An information processing device comprising: receiving means for receiving a file from an external device or network; setting means for setting an original recorded file flag for a file recorded on a recording medium to indicate whether the file is created by the information processing device or obtained externally by the receiving means; classifying means for classifying a file recorded on the recording medium according to information on a date of creation of the file; detecting means for detecting a file obtained externally among files recorded on said recording medium based on said original recorded file flag; and display control means (5; 7) for displaying a result of classification by said classifying means on a display unit; wherein when said detecting means detects the file obtained externally, said classifying means classifies the file according to information on a date of obtainment of the file by the information processing device; and said display control means (5; 7) divides a predetermined display screen of said display unit into a plurality of areas, assigns a date to each of the divided said areas, and displays, as a result of classification, at least presence of said file in said area to which a date corresponding to the information on the date of creation or the information on the date of obtainment of said file classified by said classifying means is assigned. receiving means for receiving a file from an external device or network; setting means for setting an original recorded file flag for a file recorded on a recording medium to indicate whether the file is created by the information processing device or obtained externally by the receiving means; classifying means for classifying a file recorded on the recording medium according to information on a date of creation of the file; detecting means for detecting a file obtained externally among files recorded on said recording medium based on said original recorded file flag; and display control means (5; 7) for displaying a result of classification by said classifying means on a display unit; wherein when said detecting means detects the file obtained externally, said classifying means classifies the file according to information on a date of obtainment of the file by the information processing device; and classifying means for classifying a file recorded on the recording medium according to information on a date of creation of the file; detecting means for detecting a file obtained externally among files recorded on said recording medium based on said original recorded file flag; and display control means (5; 7) for displaying a result of classification by said classifying means on a display unit; wherein when said detecting means detects the file obtained externally, said classifying means classifies the file according to information on a date of obtainment of the file by the information processing device; and said display control means (5; 7) divides a predetermined display screen of said display unit into a plurality of areas, assigns a date to each of the divided said areas, and displays, as a result of classification, at least presence of said file in said area to which a date corresponding to the information on the date of creation or the information on the date of obtainment of said file classified by said classifying means is assigned.