A fixing device includes a fixing rotary body inside which a heat generator is disposed and an exciting coil unit disposed opposite the heat generator via the fixing rotary body. A first moving mechanism is connected to one of the heat generator and the exciting coil unit to move the one of the heat generator and the exciting coil unit between a first position where the exciting coil unit is disposed away from the heat generator and a second position where the exciting coil unit is disposed closer to the heat generator. The exciting coil unit heats a first heat generation layer of the fixing rotary body at the first position, and heats both the first heat generation layer of the fixing rotary body and a second heat generation layer of the heat generator at the second position.