A method for repairing a defective semiconductor device, the defective semiconductor device including a semiconductor thin film and a conductive thin film, disposed in the named order, on a conductive surface of a substrate, such that the conductive thin film and the conductive surface of the substrate are electrically short-circuited at a pinhole occurring in the semiconductor thin film to form an electrically short-circuited portion. The method includes the steps of applying desired a voltage through an electrode positioned above a surface of the defective semiconductor device, and moving the electrode along the surface of the defective semiconductor device while maintaining a distance between the electrode and the conductive thin film sufficient to allow a discharge to occur when the electrode is above the electrically short-circuited portion, such that the discharge modifies a region of the conductive thin film which is in electrical contact with the conductive surface of the substrate, to establish an electrically noncontacted state between the conductive thin film and the conductive surface of the substrate.