A solar cell wafer having a porous layer on a surface of a semiconductor wafer typified by a silicon wafer, which can further reduce reflection loss of light at the surface. A solar cell wafer 100 of the present invention has a porous layer 11 having a pore diameter of 10 nm or more and 45 nm or less, on at least one surface 10A of a semiconductor wafer 10, and the layer thickness of the porous layer 11 is more than 50 nm and 450 nm or less.