There is disclosed an image forming apparatus to which one or more programs can be added. The image forming apparatus includes a managing part configured to manage access authorization information set for each of groups into which the programs are categorized, a displaying part configured to display a setting screen in which access authorization setting information is set in correspondence with each of the programs, a changing part configured to change a range of access authorization granted to the programs according to access authorization change information, the access authorization change information including definitions of change information corresponding to the access authorization setting information set in the setting screen, and a determining part configured to determine whether the access authorization can be granted to the programs.