A wafer production method for producing a wafer from a lithium tantalate ingot includes a step of irradiating, from an end face of a lithium tantalate ingot which is a 42-degree rotation Y cut ingot having an orientation flat formed in parallel to a Y axis, a laser beam of a wavelength having transparency to lithium tantalate with a focal point of the laser beam positioned in the inside of the ingot to form a modified layer in the inside of the ingot while the ingot is fed for processing, and a step of applying external force to the ingot to peel off a plate-shaped material from the ingot to produce a wafer. At the step of forming a modified layer, the ingot is relatively fed for processing in a direction parallel or perpendicular to the orientation flat.