To provide a method for manufacturing a wafer having an excellent warpage characteristic of warp, etc., and also to provide a wire saw for manufacturing the wafer having the excellent warpage characteristic.

In this method for manufacturing the wafer by cutting an ingot by the wire saw, the ingot is cut, while controlling tension of a wire by a tension imparting mechanism according to deflection amount of the wire of an ingot feeding direction at least during cutting of the ingot. The wire saw is used for manufacturing the wafer by pressing the ingot on the wire and cutting the ingot, while moving the wire between rollers. The wire saw is provided with a wire tension imparting mechanism and an arithmetic control unit. The wire tension imparting mechanism imparts tension to the wire. The arithmetic control unit controls tension of the wire by the wire tension imparting mechanism according to the deflection amount of the wire of the ingot feeding direction during the cutting of the ingot.