An image forming apparatus includes a document box, a communication unit, a console unit, a referencing entity management table, and a control unit. The console unit accepts a delete operation of inputting a delete instruction to delete document data stored in the document box. The referencing entity management table allows information about another image forming apparatus referencing document data stored in the document box to be registered therein as referencing entity information. The control unit determines whether or not the document data to be deleted designated by the delete instruction input by the delete operation is referenced by another image forming apparatus, based on the referencing entity management table. The control unit, if the document data to be deleted is referenced by another image forming apparatus, causes the communication unit to transmit the document data to be deleted to the another image forming apparatus based on the referencing entity information.