Discussed is a solar cell including a photoelectric conversion portion, and first and second electrodes connected to the photoelectric conversion portion, wherein at least one of the first and second electrodes includes a plurality of finger electrodes, and at least one bus bar electrode formed in a direction crossing the finger electrodes, wherein the bus bar electrode includes a main bus bar, and an auxiliary bus bar formed adjacent to the main bus bar such that the auxiliary bus bar is spaced from the main bus bar by a predetermined spacing area, and wherein the spacing area has a width equal to or less than a pitch of the plurality of finger electrodes.