A solar cell comprising: a semiconductor substrate ; an emitter layer formed at a front surface of the semiconductor substrate , the emitter layer being of a conductive type different from that of the semiconductor substrate ; a first electrode having a plurality of first fingers , electrically connected to the emitter layer ; a back surface field layer having a plurality of first portions locally formed at a back surface of the semiconductor substrate at a first pitch (P1, P2) along a direction perpendicular to the longitudinal direction of the first portions , the back surface field layer being of the same conductive type as that of the semiconductor substrate ; and a second electrode having a plurality of second fingers arranged at a first pitch (P1, P2)and electrically connected to the plurality of first portions of the back surface field layer , wherein the plurality of first portions of the back surface field layer and the plurality of second fingers extend in a same direction, wherein the plurality of first portions of the back surface field layer and the plurality of second fingers have connecting projections protruding from the first portions and the second fingers , the connecting projections extending parallel to the back surface in a direction perpendicular to the direction in which the first portions and the second fingers extend, and the connecting projections being spaced apart from one another by a second pitch (P22), wherein each connecting projection includes a first protruding portion formed at one side of the first portions and the second fingers , and a second protruding portion formed at the opposite side of the first portions and the second fingers , and wherein the first protruding portion and the second protruding portion are alternately arranged on the first portions and the second fingers . a semiconductor substrate ; an emitter layer formed at a front surface of the semiconductor substrate , the emitter layer being of a conductive type different from that of the semiconductor substrate ; a first electrode having a plurality of first fingers , electrically connected to the emitter layer ; a back surface field layer having a plurality of first portions locally formed at a back surface of the semiconductor substrate at a first pitch (P1, P2) along a direction perpendicular to the longitudinal direction of the first portions , the back surface field layer being of the same conductive type as that of the semiconductor substrate ; and a second electrode having a plurality of second fingers arranged at a first pitch (P1, P2)and electrically connected to the plurality of first portions of the back surface field layer , wherein the plurality of first portions of the back surface field layer and the plurality of second fingers extend in a same direction, wherein the plurality of first portions of the back surface field layer and the plurality of second fingers have connecting projections protruding from the first portions and the second fingers , the connecting projections extending parallel to the back surface in a direction perpendicular to the direction in which the first portions and the second fingers extend, and the connecting projections being spaced apart from one another by a second pitch (P22), wherein each connecting projection includes a first protruding portion formed at one side of the first portions and the second fingers , and a second protruding portion formed at the opposite side of the first portions and the second fingers , and wherein the first protruding portion and the second protruding portion are alternately arranged on the first portions and the second fingers . <EOS>