To provide a hair iron which shortens the application time, is neat in the finish after the application and hardly damages the hair.

The hair is moved at a prescribed speed between magnets 13 of which S poles are disposed to face each other after the application of a first liquid to the hair. Reduction energy is, therefore, generated from the S poles of the magnets 13 in which the electrons of the magnetic poles are rotated clockwise by Fleming's right-hand rule. As a result, the reduction effect of the first liquid is accelerated. A cuticle is closed to prevent the intrusion of UV rays into the hair. The clusters of the water of the first liquid are made smaller by the reduction energy and the penetratability of the first liquid into the hair is enhanced. Consequently, the reduction effect of the first liquid is further accelerated and the time required for the application which is liable to be accompanied by the damage of the hair may be shortened. Accordingly, the finish after the application is made neat and the hair may be made hardly damaged.