1. An image file processing method adopted in an image file processing apparatus, comprising steps for: inputting an image file; making a decision as to whether or not the input image file uses a specific color space based upon color space identification information that is stored in the input image file and indicates whether or not the specific color space is used in the input image file; converting the specific color space to a color space suitable for processing to be executed in the image processing apparatus by using a first information stored in advance in the image processing apparatus if the input image file is determined to use the specific color space; and converting a color space used in the input image file to the color space suitable for the processing to be executed in the image processing apparatus by using a second information stored in the input image file if the input image file is determined to use a color space other than the specific color space, the second information being information different from the color space identification information.