A method for manufacturing a solar-power-generator substrate by cutting out a semiconductor substrate by slicing a semiconductor ingot and then by forming a texture structure on a surface of the semiconductor substrate by performing a surface treatment on the surface of the semiconductor substrate, includes: cleaning including cleaning and removing an organic impurity and a metal impurity adhering to the surface of the semiconductor substrate with a cleaning fluid containing an oxidizing chemical; and etching including removing a damaged layer on a substrate surface generated by the slicing and forming the texture structure on the surface of the semiconductor substrate by performing anisotropic etching on the surface of the semiconductor substrate with an alkaline aqueous solution, the etching being performed subsequent to the cleaning.