A method of fabricating a solar cell forms a large number of grooves on a first main surface of a p-type silicon single crystal substrate sliced out from a silicon single crystal ingot as described below. First an edge portion of a groove-carving blade is projected out from a flat substrate feeding surface of a working table by a predetermined height. The p-type silicon single crystal substrate is moved along the substrate feeding surface towards the rotating groove-carving blade while keeping a close contact of the first main surface thereof with the substrate feeding surface. Electrodes are then formed on the inner side face of thus-carved grooves only on one side in the width-wise direction thereof.