A carrier plate removing method for removing a carrier plate from a workpiece previously provided through a temporary bonding layer on the front side of the carrier plate is provided. The carrier plate removing method includes a shoulder portion forming step of processing a peripheral portion of the carrier plate along a peripheral edge thereof from the front side of the carrier plate on which the workpiece is provided, thereby forming a shoulder portion as a lower part connected to the back side of the carrier plate, the lower part projecting horizontally outward from the side surface of an upper part connected to the front side of the carrier plate.