To provide an image forming apparatus in which its own machine information specifying at least the printer and the print date can be printed out as attribute data along with image data, and processing of printed sheets left as they are is facilitated without casting a burden on a user.

A control section 10 converts date information read out from a timer 21, its own machine information (name of section installing the machine and machine number) read out from a section 12a storing its own machine information, terminal information (name of section installing the terminal and user name) read out from a section 12b storing terminal information, or personal information (name of belonging section and individual name) read out from a section 12c storing personal information into attribute data of bit image by means of a decoder 23, stores that data in a page memory 26, and prints out the attribute data read out from the page memory 26 on the rear surface of a recording sheet from a recording section 25.