A hair iron 1 includes a pair of grips 9 being rotatably connected to a base end so as to be openable and closable; and a heating part 11 being provided to be opposed to a tip end side of each grip 9 wherein each heating part 11 has a flat opposing surface, a rear surface side of the heating part 11 has a curved curling part 13, and at least one curling part 13 has an auxiliary case 15 with a curved surface having a different curvature from that of the curling part 13 so as to be attachable and detachable thereto and therefrom.