A method for manufacturing a semiconductor layer according to an embodiment of the present invention comprises preparing a first compound, preparing a second compound, making a semiconductor layer forming solution, and forming a semiconductor layer including a group compound by using this semiconductor layer forming solution. The first compound contains a first chalcogen-element-containing organic compound, a first Lewis base, a I-B group element, and a first III-B group element. The second compound contains an organic ligand and a second III-B group element. The semiconductor layer forming solution contains the first compound, the second compound, and an organic solvent.