1. A method for performing a maintenance operation for cleaning a printing unit of an image forming apparatus, the method comprising the steps of: (a) recording printing work information as usage pattern information when a command for the maintenance operation is entered and recording setup information for performing the maintenance operation; (b) counting and recording the printing work information of printing data upon input of a printing command; and (c) comparing the usage pattern information with the counted printing work information and, when the counted printing work information is equal to the usage pattern information, performing the maintenance operation; (d) when the usage pattern information does not equal the counted printing work information, determining whether the setup information is equal to the counted printing work information; and (e) when the setup information is equal to the counted printing work information, performing the maintenance operation of cleaning the printing unit.