A solar cell includes a support substrate; a back electrode layer on the a support substrate; a light absorbing layer on the back electrode layer; a buffer layer on the light absorbing layer; a front electrode layer on the buffer layer; and a fourth through hole formed through the back electrode layer, the light absorbing layer, the buffer layer and the front electrode layer, wherein at least a portion of the fourth through hole is inclined with respect to a top surface of the support substrate.