The present invention provides a fixing device. A fixing roller (3) is provided with a limiting component (40) which abuts against a twisted fixing tape (5) and moves in an axial direction. A heating roller (6) which gets close and separated relatively to the fixing roller is provided with an adjusting component (41). The motion of the adjusting component and the limiting component cause the motion of the heating roller in an interaxial direction which is orthogonal with the axial direction. The adjusting component is unmovable in the axial direction and is movable in the interaxial direction. The twisted fixing tape deviates to one side of the axial direction and touches the limiting component. The limiting component (40) is pushed by the fixing tape (5) for moving to one side. The adjusting component (41) is pushed by the limiting component (40) for moving in the interaxial direction. The heating roller (6) moves with a mode of separating from the fixing roller (3). An axial distance between the fixing roller (3) and one side of the heating roller (6) increases, and the fixing tape (5) moves to the other side. Therefore, the twist can be prevented without applying force to the twisted fixing tape (5).