A method of disconnecting a short-circuited part between upper and lower electrodes is provided which comprises the steps of;(a) forming a cell by placing one upon another a first substrate provided with a common electrode and a second substrate provided with opposed electrodes in the manner that said common electrode and said opposed electrode may form a plurality of mutually opposed portions;(b) detecting, among the plurality of mutually opposed portions, a mutually opposed portion at which a short circuit has occurred; and(c) disconnecting by insulation a short-circuited site present at the mutually opposed portion from the common electrode or opposed electrode.