Manufacturing method of wafer and wafer

Included are a resin layer forming step for forming a resin layer (R) on one surface (W1) of a wafer (W); a first surface grinding step in which the one surface (W1) is held and another surface (W2) is subjected to surface grinding with the resin layer (R) interposed between; a resin layer removal step for removing the resin layer (R); and a second surface grinding step in which the other surface (W2) is held, and the one surface (W1) is subjected to surface grinding. In the resin layer forming step, the resin layer (R) is formed so as to satisfy formula (1) below. T/X > 30 (1) (where X is the maximum amplitude of undulations for which the wavelength with the wafer is 10–100 mm inclusive, and T is the thickness of the thickest part of the resin layer)