A fixing device is configured to fix a toner image to a sheet by heat and includes: a heating rotator; a pressurizing roller contacting with the heating rotator; a heater configured to heat the heating rotator such that the heat is transferred to the sheet passing through a contact portion between the heating rotator and the pressurizing roller; a plurality of separation claws configured to separate the sheet from the heating rotator such that the sheet passing through the contact portion is not caught in the heating rotator, the separation claws being provided opposite to the heating rotator; and an adjustor configured to adjust positions of the separation claws relative to the heating rotator such that distances between the separation claws and the heating rotator are equal to each other.