A method of manufacturing semiconductor wafers which facilitates formation of orientation flat lines and allows beveling work without problems. The method of manufacturing semiconductor wafers includes steps wherein a plurality of small-diameter wafers is cut out from a large-diameter semiconductor wafer, the method including: a marking step of forming straight groove-like orientation flat lines by a laser beam so as to cross the respective small-diameter wafers in each row in the large-diameter semiconductor wafer, wherein cutout positions of the small-diameter wafers are aligned in rows in a specific direction, collectively for each of the rows; and a cutting step of cutting out the small-diameter wafers separately from the large-diameter semiconductor wafer, by a laser beam, after the marking step, in such a way that the orientation flat lines are located at required positions in the small-diameter wafers to be obtained.