To fabricate narrow front contact grooves on a single crystalline silicon solar cell, we carried out etching of a silicon nitride film on a silicon substrate using the surface discharge plasma operated at atmospheric pressure. The control of groove width by changing the discharge voltage (V (d)) and the length of a back electrode (l) used for formation of the surface discharge was examined. It was found that narrower electrode grooves could be obtained when l was short. For the case of l = 2 mm, the narrowest groove of 116 mu m was obtained at V (d) = 3.5 kV and the processing time (t (e)) of 10 s.