A fixing device mounted in an electrophotographic image forming apparatus, for fixing a toner image formed on recording paper includes: a plurality of peeling claws provided for peeling off the recording paper from a fixing roller; a number-of-processed-sheet detecting portion for detecting a number of processed sheets of recording paper which is treated with a fixing process upon passing through the fixing roller; a peeling claw driving section for moving a plurality of the peeling claws in parallel with an axial direction of the fixing roller; and a control unit for controlling the peeling claw driving section to operate so that a relative position between the peeling claw and the fixing roller changes according to a detected output of the number-of-processed-sheet detecting portion.