Patent ID: 8649034

Claim:
An image forming apparatus comprising: a mounting portion on which an external memory device is mountable; a detecting unit configured to detect mounting and non-mounting of the external memory device to the mounting portion; a printing unit configured to print data acquired from the external memory device; a memory unit configured to store the data; and a controller configured to control the printing unit to reprint the data stored on the memory unit, and prohibit the data from being reprinted when a detection result by the detecting unit indicates non-mounting of the external memory device, wherein the controller is configured to prohibit the data from being reprinted by setting a permission flag of the data to a prohibited state so as to prohibit the printing unit from reprinting the data, and to later allow the reprinting of the data prohibited from being reprinted by setting the permission flag of the data to an allowed state when a detection result by the detection unit indicates mounting of the external memory device so as to allow the printing unit to reprint the data.