A calibration method includes acquiring a captured image of a lattice fringe by providing a reference gauge having a reference surface whose height from a reference plane changes in a first direction, projecting a fringe pattern having the same phase along the first direction with respect to the reference surface and having a phase changing in a second direction crossing the first direction, and imaging the fringe pattern; calculating a phase of each pixel along the first direction in the captured image of the fringe pattern; and generating relational data in which the height of the reference surface corresponding to the pixel, the phase calculated with respect to the pixel, and a period of the fringe pattern at the time of calculating the phase are associated with each other.