A solar cell, comprising: a semiconductor substrate; a conductive region (20, 30) on or at the semiconductor substrate; and an electrode (42, 44) electrically connected to the conductive region (20, 30), wherein the electrode (42, 44) comprises a plurality of finger lines (42a, 44a) formed in a first direction and parallel to each other, and a bus bar (42b, 44b) electrically connected to the plurality of finger lines (42a, 44a) and formed in a second direction crossing the first direction, and wherein the bus bar (42b, 44b) comprises a plurality of pad portions positioned in the second direction and a line portion extending and connecting the plurality of pad portions in the second direction, wherein the plurality of pad portions comprise two outer pads positioned at opposite ends of the bus bar (42b, 44b) in the second direction, and a plurality of inner pads positioned between the two outer pads, wherein the plurality of inner pads comprise a plurality of first pads positioned in two first regions of the bus bar (42b, 44b) and a plurality of second pads positioned in a second region of the bus bar (42b, 44b), wherein the second region is positioned at an intermediate region in the second direction between the two first regions, and the two first regions are positioned at both sides of the second region, wherein the plurality of first pads in each of the first regions are spaced apart from each other at a first interval and the plurality of second pads in the second region are spaced apart from each other at a second interval greater than the first interval, wherein the plurality of inner pads all have an equal area, wherein at least one of the plurality of finger lines (42a, 44a) is disposed between two neighboring inner pads of the plurality of inner pads, and a number of the plurality of finger lines (42a, 44a) disposed between two neighboring first pads is smaller than a number of the plurality of finger lines (42a, 44a) disposed between two neighboring second pads in the second direction, and wherein a length of each of the outer pads in the second direction is longer than a length of each of the plurality of inner pads in the second direction, and an area of each of the outer pads is greater than the area of each of the plurality of inner pads, wherein the outer pads are spaced from the first regions by a third interval greater than the first interval. a semiconductor substrate; a conductive region (20, 30) on or at the semiconductor substrate; and an electrode (42, 44) electrically connected to the conductive region (20, 30), wherein the electrode (42, 44) comprises a plurality of finger lines (42a, 44a) formed in a first direction and parallel to each other, and a bus bar (42b, 44b) electrically connected to the plurality of finger lines (42a, 44a) and formed in a second direction crossing the first direction, and wherein the bus bar (42b, 44b) comprises a plurality of pad portions positioned in the second direction and a line portion extending and connecting the plurality of pad portions in the second direction, wherein the plurality of pad portions comprise two outer pads positioned at opposite ends of the bus bar (42b, 44b) in the second direction, and a plurality of inner pads positioned between the two outer pads, wherein the plurality of inner pads comprise a plurality of first pads positioned in two first regions of the bus bar (42b, 44b) and a plurality of second pads positioned in a second region of the bus bar (42b, 44b), wherein the second region is positioned at an intermediate region in the second direction between the two first regions, and the two first regions are positioned at both sides of the second region, wherein the plurality of first pads in each of the first regions are spaced apart from each other at a first interval and the plurality of second pads in the second region are spaced apart from each other at a second interval greater than the first interval, wherein the plurality of inner pads all have an equal area, wherein at least one of the plurality of finger lines (42a, 44a) is disposed between two neighboring inner pads of the plurality of inner pads, and a number of the plurality of finger lines (42a, 44a) disposed between two neighboring first pads is smaller than a number of the plurality of finger lines (42a, 44a) disposed between two neighboring second pads in the second direction, and wherein a length of each of the outer pads in the second direction is longer than a length of each of the plurality of inner pads in the second direction, and an area of each of the outer pads is greater than the area of each of the plurality of inner pads, wherein the outer pads are spaced from the first regions by a third interval greater than the first interval.