A fixing device for thermally fixing onto a sheet, an unfixed image formed on the sheet, includes: an endless belt that is heated by electromagnetic induction while being driven to rotate; a curved member that is positioned inside a rotation path of the belt and that is curved in an arc shape along the rotation path of the belt; a magnetic flux generator that (i) is positioned outside the rotation path of the belt, facing the curved member with the belt in between, and (ii) generates magnetic flux for heating the belt; a heat generation layer that is provided on the belt; a magnetic shunt alloy layer that is provided along the curved member, facing a protruding side of the curved member; and a magnetic flux nullifying layer that is provided on the curved member.