A fixing device (7) includes a fixing member (21), a pressing member (22), a rotation detector (41), and an auxiliary driving part (42). The fixing member (21), with rotating around an axis, heats a toner image on a medium (S). The pressing member (22), with rotating around an axis, forms a pressing area (N) with the fixing member (21) and presses toner on the medium (S) passing through the pressing area (N). The rotation detector (41), when the medium (S) stops while being sandwiched between the fixing member (21) and the pressing member (22), detects rotation of the fixing member (21) or the pressing member (22) generated in a process of extracting the medium (S) toward an upstream side or a downstream side in a passing direction. The auxiliary driving part (42), while the medium (S) is being extracted, determines a rotating direction of the fixing member (21) or the pressing member (22) based on a detection result by the rotation detector (41), and rotates the fixing member (21) or the pressing member (22) in the rotating direction.