A solar cell includes a semiconductor substrate including a first conductive type, a first amorphous silicon thin film layer disposed on the semiconductor substrate and a second amorphous silicon thin film layer including a second conductive type and disposed on the first amorphous silicon thin film layer. The first amorphous silicon thin film layer includes a first intrinsic silicon thin film layer, a second intrinsic silicon thin film layer facing the semiconductor substrate while interposing the first intrinsic silicon thin film layer therebetween and a first low concentration silicon thin film layer including the second conductive type and disposed between the first intrinsic silicon thin film layer and the second intrinsic silicon thin film layer.