To maintain a state where paper peeling oil does not remain on the surface of a fixing roll.

This image forming device is constituted of a fixing device F provided with a heating roll Fh and an oil coating roll 54 applying the sheet peeling oil for peeling a recording sheet S from the surface of the roll Fh by moving to an oil coating position where it comes in contact with the roll Fh, an oil coating start time detection means calculating oil coating start time t3=(t1-ta) from a moving time (ta) from the oil coating position on the surface of the roll Fh to the upstream end of a fixing area QF and time t1 when the front end of the sheet S advances to the upstream end of the fixing area QF, an oil coating finish time detection means calculating oil coating finish time t4=(t2-ta) from time t2 when the rear end of the sheet S advances to the upstream end of the fixing area QF, and a coating roll moving control means controlling the roll 54 to move to the oil coating position only in a period from the start time t3 till the finish time t4.