A correction method for correcting measurement error in data obtained when
a stylus tip of a measurement apparatus that moves following the height
of a workpiece traces the workpiece along a measurement axis, the
measurement error having occurred due to stylus movement in a plane
defined by the measurement axis and height directions, the method
includes a calibration measurement process of obtaining calibration
measurement data that includes shift information on the position of the
stylus tip, corresponding to the position of the stylus tip in the height
directions while the stylus is moved in the correction target plane and a
correction-parameter setting process obtaining a correction parameter
value optimal to correct the shift information on the position of the
stylus tip, included in the calibration measurement data, for each of the
sectors obtained by dividing a measurement range in the height
directions.