The invention provides a wafer polishing apparatus and a wafer manufacturing method which can improve uniformity in polishing wafer surfaces. A wafer holding head comprises a head body; a diaphragm stretched inside the head body; a carrier fixed to the diaphragm to be displaceable in the direction of a head axis while holding the wafer; a retainer ring disposed around the carrier in concentric relation and fixed to the diaphragm to be displaceable in the direction of the head axis; and a thin plate disposed so as to project from the head body along a surface of the diaphragm. With the provision of the thin plate, an excessive pressing force acting upon the retainer ring from the diaphragm is suppressed, and the wafer surface can be prevented from being excessively polished at an outer peripheral edge.