IMAGE FORMING APPARATUS AND FIXING DEVICE

PROBLEM TO BE SOLVED: To efficiently perform the process of continuously fixing developer images to mediums while altering conditions.SOLUTION: The invention relates to an image forming apparatus that has a fixing device. The fixing device comprises: means for performing a fixing process in which a developer image is fixed to a medium using a fixing member and heating means for heating the fixing member; heating control means configured to control the operation of the heating means so that the temperature of the fixing member is within a set target temperature range; and means configured such that a first target temperature range corresponding to a first medium is set for the heating control means when the fixing means performs a fixing process on the first medium, and that the target temperature range set for the heating control means is made closer to a second target set temperature range corresponding to a second medium on which a fixing process is performed subsequent to the first medium.