A technique was developed to heal a fatigue crack by controlling a high density electric current field. The high-density electric current field was applied at the tip of the crack by using closely spaced electrodes. It was found that the electric stimulation influences the states and propagation behavior of a fatigue crack in the stainless steel. When the electric current was applied to a specimen having a pre-crack with a large opening displacement, a closure effect at the crack tip was shown and the bridges between the crack surfaces were observed. On the other hand, when the electric current was applied to a specimen having a pre-crack with a small opening displacement, an opening effect was shown. These effects were also evaluated quantitatively by the Paris law.