A fixing device for fixing a toner image on a recording medium includes first and second belts rotatably disposed opposite to each other such that the recording medium having the toner image thereon moves therebetween, a fixing roller disposed in contact with an inner surface of the first belt, a pressure roller disposed in contact with an inner surface of the second belt, the fixing and pressure rollers forming a first nip part therebetween, a first supporting member disposed downstream of the fixing roller and held in contact with the inner surface of the first belt, and a second supporting member disposed downstream of the pressure roller and held in contact with the inner surface of the second belt. A second nip part is formed downstream of the first nip portion and upstream of the first and second supporting members facing each other via the first and second belts.