Image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet of a recording material;
• a fixing unit configured to fix the image formed by the image forming unit to the sheet and comprising a heating member configured to contact the sheet to heat the image on the sheet;
• and
• a control unit configured to control the image forming unit and the fixing unit,
• the control unit being configured to:
• in executing a job to form images continuously on a plurality of sheets of a recording material by the image forming unit and the fixing unit, accumulate an addition amount per sheet to an index regarding a temperature of the heating member in accordance with a number of sheets of the recording material to which images are formed in the job, wherein a value of the addition amount per sheet to be accumulated to the index is one of values predetermined in correspondence with attributes of recording materials, and is determined in correspondence with an attribute of the recording material used in the job;
• and
• during execution of the job, change a throughput of the job so that images are formed at a first throughput if an accumulated value of the index still does not exceed a predetermined threshold value and images are formed at a second throughput slower than the first throughput if the accumulated value of the index has exceeded the threshold value.