Wafer and wafer producing method

A wafer producing method of producing a wafer from a hexagonal single crystal ingot, the method comprising:

• a peel-off layer forming step of applying a laser beam of a wavelength passing through the hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of a wafer to be produced from an end face of the hexagonal single crystal ingot to form a peel-off layer;
• a production history forming step of applying a laser beam of a wavelength passing through the wafer with a focal point of the laser beam positioned inside the wafer at a position corresponding to each of a plurality of devices to be formed on a front surface of the wafer to form a production history;
• and
• a wafer peeling step of peeling off the wafer from the hexagonal single crystal ingot at least after the peel-off layer forming step is carried out.