Optical device wafer processing method

A processing method for an optical device wafer having a device area where a plurality of optical devices are formed on the front side of a sapphire substrate and a peripheral marginal area surrounding said device area, said device area projecting from said peripheral marginal area, said processing method comprising:

• a break start point forming step of applying a laser beam along the boundary between said device area and said peripheral marginal area of said optical device wafer to thereby form a break start point on the front side of said sapphire substrate;
• a protective member attaching step of attaching a protective member to the front side of said optical device wafer;
• and
• a back grinding step of holding said optical device wafer on a chuck table of a grinding apparatus in the condition where said protective member attached to the front side of said optical device wafer comes into contact with a holding surface of said chuck table after performing said break start point forming step and said protective member attaching step, and next grinding the back side of said sapphire substrate to reduce the thickness thereof to a predetermined thickness.