Image forming apparatus

An image forming apparatus for receiving a print job having data addition authentication information and print-outputting on the basis of a result of a collation with print request authentication information, comprising:

• data addition authentication information detecting section which detects said data addition authentication information from said print job;
• transmitting source specifying section which specifies a transmitting source of said print job;
• a storing unit which stores said detected data addition authentication information, said specified transmitting source of the print job, and the print job having said data addition authentication information;
• an input unit which receives said print request authentication information;
• elapsed time measuring section which measures an elapsed time from the reception of the print job having said data addition authentication information;
• erasure extension necessity inquiry section which requests an answer about necessity of an erasing time extension from said transmitting source when a result of the measurement by said elapsed time measuring section indicates elapse of a predetermined time;
• and
• erasure/extension decision processing section which, if the answer result by said erasure extension necessity inquiry section indicates that the erasure extension is necessary, extends an elapsed time until said print job is erased after the reception of said print job by a predetermined time.