To provide a polishing method which does not cause a chip in an outer periphery of a plate-like object and does not deteriorate flatness of a polished surface.

A polishing method of a plate-like object for polishing a rear surface of the plate-like object with a polishing pad having a polishing surface whose radius is greater than a diameter of the plate-like object comprises a holding step of holding a surface side of the plate-like object on a chuck table having a holding surface on which the plate-like object is held and a polishing step of polishing the plate-like object by rotating a spindle on which the polishing pad is installed with the entire rear surface of the plate-like object held on the chuck table being covered by a polishing surface of the polishing pad. In the polishing step, a rotational axis of the spindle and a rotational axis of the chuck table are relatively inclined so that the polishing surface and the holding surface relatively incline in a separation direction from a rotation center of the polishing pad toward the outside, and the plate-like object is polished.