A fixing device incorporated in an image recording apparatus has a heater 24 for fixing an image formed on a sheet 11 by heating a toner 12 constituting the image, and a thin endless belt 21 for carrying the sheet 11. The endless belt 21 is rotated by a drive roller 22 and is given tension by a tension roller 23. A tapered member 26a is located at an end of the tension roller 23 and a guide member 30 contacts with a side tapered surface of the tapered member. When the endless belt 21 skews, the tension roller 23 moves along its axis by a reaction force and inclines in a direction parallel to a tension direction of the tension roller 23 to compensate for the skew.