A fixing device includes a fixing belt, a pressuring member, a heat source, a pressing member, a heating stop device, shape restricting members and biasing members. The fixing belt is provided to be rotatable around a rotation axis. The pressing member is provided to be rotatable and to come into pressure contact with the fixing belt so as to form a fixing nip. The heat source heats the fixing belt. The pressing member presses the fixing belt to a side of the pressuring member. The heating stop device faces an outer circumferential face of the fixing belt and to operate at an operating temperature so as to stop the heat source from heating the fixing belt. The shape restricting members are attached to both end parts of the fixing belt and restricts a shape of the fixing belt.