A file management method for managing files of image data photographed with an image pickup apparatus, the files being classified into directories every predetermined number of files in accordance with numerical values included in their file names, the method comprising a) a counting step of updating a current numerical value every image data recording, b) a generating step of generating the file name including as a part thereof said current numerical value when data of one of the photographed images is recorded as a file on a recording medium and storing the data in a file with the generated file name, and c) a storing step of storing the current numerical value updated in said counting step, into a nonvolatile memory of said image pickup apparatus, d) adding 1 to the current numerical value in said counting step every image data recording, and wherein the method further comprises, when the power source of the image pickup apparatus is turned on or the recording medium is changed: e) obtaining a maximum directory number of directories stored on the recording medium for storing a recorded image: f) comparing a current directory number based on the current numerical value with the maximum directory number; and g) if the current directory number is not larger than the maximum directory number: obtaining the maximum value of the numerical values included in the file names already stored in the directory having the maximum directory number, comparing the obtained maximum value with the current numerical value, and changing the current numerical value to be the obtained maximum value plus 1 in case the current numerical value is not larger than the obtained maximum value of the file names. a) a counting step of updating a current numerical value every image data recording, b) a generating step of generating the file name including as a part thereof said current numerical value when data of one of the photographed images is recorded as a file on a recording medium and storing the data in a file with the generated file name, and c) a storing step of storing the current numerical value updated in said counting step, into a nonvolatile memory of said image pickup apparatus, d) adding 1 to the current numerical value in said counting step every image data recording, and wherein the method further comprises, e) obtaining a maximum directory number of directories stored on the recording medium for storing a recorded image: f) comparing a current directory number based on the current numerical value with the maximum directory number; and g) if the current directory number is not larger than the maximum directory number: obtaining the maximum value of the numerical values included in the file names already stored in the directory having the maximum directory number, comparing the obtained maximum value with the current numerical value, and changing the current numerical value to be the obtained maximum value plus 1 in case the current numerical value is not larger than the obtained maximum value of the file names. obtaining the maximum value of the numerical values included in the file names already stored in the directory having the maximum directory number, comparing the obtained maximum value with the current numerical value, and changing the current numerical value to be the obtained maximum value plus 1 in case the current numerical value is not larger than the obtained maximum value of the file names.