A solar cell comprising: a substrate; an emitter layer at a first surface of the substrate; a first insulating layer on a first surface of the emitter layer, the first insulating layer having a plurality of first openings that expose portions of the emitter layer; and a plurality of first electrodes having a line shape extending in a first direction and electrically connected to the emitter layer through the first openings, wherein one or more of the first electrodes are configured so that a width in a second direction crossing the first direction of an upper portion located on the first insulating layer is wider than a width (W1') in the second direction of a lower portion located in a corresponding first opening, a plurality of first current collectors formed in a direction crossing the plurality of first electrodes, having a line shape extending in the second direction and connected to the plurality of first electrodes, characterized in that: the plurality of first electrodes and the plurality of first current collectors have the same structure, a width in the second direction of a first opening is less than half a width in the second direction of an upper portion of the first electrodes, the first insulating layer further comprises a plurality of second openings that expose portions of the emitter layer, at least two second openings are located at each first current collector; the at least two second openings are spaced apart from each other in the first direction of the first current collectors; the first insulating layer includes a first upper layer and a first lower layer between the first upper layer and the emitter layer, and a first opening of the plurality of first openings is formed so that a width (W2-2) in the second direction of the first opening at the first lower layer is different from a width (W2-1) in the second direction of the first opening at the first upper layer and, so that an area and average diameter of the first opening is greater at the first lower layer than at the first upper layer. a substrate; an emitter layer at a first surface of the substrate; a first insulating layer on a first surface of the emitter layer, the first insulating layer having a plurality of first openings that expose portions of the emitter layer; and a plurality of first electrodes having a line shape extending in a first direction and electrically connected to the emitter layer through the first openings, wherein one or more of the first electrodes are configured so that a width in a second direction crossing the first direction of an upper portion located on the first insulating layer is wider than a width (W1') in the second direction of a lower portion located in a corresponding first opening, a plurality of first current collectors formed in a direction crossing the plurality of first electrodes, having a line shape extending in the second direction and connected to the plurality of first electrodes, characterized in that: the plurality of first electrodes and the plurality of first current collectors have the same structure, a width in the second direction of a first opening is less than half a width in the second direction of an upper portion of the first electrodes, the first insulating layer further comprises a plurality of second openings that expose portions of the emitter layer, at least two second openings are located at each first current collector; the at least two second openings are spaced apart from each other in the first direction of the first current collectors; the first insulating layer includes a first upper layer and a first lower layer between the first upper layer and the emitter layer, and a first opening of the plurality of first openings is formed so that a width (W2-2) in the second direction of the first opening at the first lower layer is different from a width (W2-1) in the second direction of the first opening at the first upper layer and, so that an area and average diameter of the first opening is greater at the first lower layer than at the first upper layer. the plurality of first electrodes and the plurality of first current collectors have the same structure, a width in the second direction of a first opening is less than half a width in the second direction of an upper portion of the first electrodes, the first insulating layer further comprises a plurality of second openings that expose portions of the emitter layer, at least two second openings are located at each first current collector; the at least two second openings are spaced apart from each other in the first direction of the first current collectors; the first insulating layer includes a first upper layer and a first lower layer between the first upper layer and the emitter layer, and a first opening of the plurality of first openings is formed so that a width (W2-2) in the second direction of the first opening at the first lower layer is different from a width (W2-1) in the second direction of the first opening at the first upper layer and, so that an area and average diameter of the first opening is greater at the first lower layer than at the first upper layer.