A method for fabricating a solar cell is provided and has steps of: providing a transparent conductive substrate; forming a porous supporting layer on the transparent conductive substrate; forming a porous conductive counter electrode layer on the porous supporting layer, where the porous conductive counter electrode layer includes a carrier blocking layer and a conductive layer, and the carrier blocking layer is between the porous supporting layer and the conductive layer; and providing a light-absorbing material penetrating from the porous conductive counter electrode layer. The light-absorbing material fills within the porous supporting layer through a plurality of pores in the porous conductive counter electrode layer.