A solar cell comprising: a semiconductor substrate doped with impurities of a first conductive type; an emitter region doped with impurities of a second conductive type opposite the first conductive type and extending in a first direction; a back surface field region more heavily doped than the semiconductor substrate with impurities of the first conductive type and extending in the first direction in parallel with the emitter region; a first electrode positioned on a back surface of the semiconductor substrate, electrically connected to the emitter region and extending in the first direction; and a second electrode positioned on the back surface of the semiconductor substrate, electrically connected to the back surface field region and extending in the first direction, characterized in that the first electrode has different linewidths (WE1, NE1) at two positions that are separated from each other in the first direction, the second electrode has different linewidths (WE2, NE2) at two positions that are separated from each other in the first direction, and a linewidth of the first electrode and a linewidth of the second electrode are different from each other at two positions that are separated from each other in a second direction crossing the first direction, as the first electrode goes along the first direction, the first electrode repeatedly has a portion having a first maximum linewidth and a portion having a first minimum linewidth less than the first maximum linewidth, as the second electrode goes along the first direction, the second electrode repeatedly has a portion having a second maximum linewidth and a portion having a second minimum linewidth less than the second maximum linewidth, wherein the linewidth of the first electrode gradually increases or decreases between the first minimum linewidth and the first maximum linewidth, and the linewidth of the second electrode gradually increases or decreases between the second minimum linewidth and the second maximum linewidth. a semiconductor substrate doped with impurities of a first conductive type; an emitter region doped with impurities of a second conductive type opposite the first conductive type and extending in a first direction; a back surface field region more heavily doped than the semiconductor substrate with impurities of the first conductive type and extending in the first direction in parallel with the emitter region; a first electrode positioned on a back surface of the semiconductor substrate, electrically connected to the emitter region and extending in the first direction; and a second electrode positioned on the back surface of the semiconductor substrate, electrically connected to the back surface field region and extending in the first direction, characterized in that the first electrode has different linewidths (WE1, NE1) at two positions that are separated from each other in the first direction, the second electrode has different linewidths (WE2, NE2) at two positions that are separated from each other in the first direction, and a linewidth of the first electrode and a linewidth of the second electrode are different from each other at two positions that are separated from each other in a second direction crossing the first direction, as the first electrode goes along the first direction, the first electrode repeatedly has a portion having a first maximum linewidth and a portion having a first minimum linewidth less than the first maximum linewidth, as the second electrode goes along the first direction, the second electrode repeatedly has a portion having a second maximum linewidth and a portion having a second minimum linewidth less than the second maximum linewidth, wherein the linewidth of the first electrode gradually increases or decreases between the first minimum linewidth and the first maximum linewidth, and the linewidth of the second electrode gradually increases or decreases between the second minimum linewidth and the second maximum linewidth.