A fixing device includes: a fixing roll member; a support roll member; a fixing belt member rotated while being mounted on and tensioned by the fixing roll member and the support roll member; a roll heating unit that heats the fixing roll member; a belt heating unit that heats the fixing belt member; a pressing member that is in press contact with a portion of the fixing roll member, around which the fixing belt member is wound, to form a nip portion; and a temperature controlling device that controls and drives the roll heating unit and the belt heating unit. The temperature controlling device controls the fixing roll member and the fixing belt member to be different temperatures.