MEASUREMENT METHOD

PROBLEM TO BE SOLVED: To provide technology advantageous to a reduction in a calculation load required to connect (stitch) measurement data of a partial area in measuring the surface shape of a plane to be measured.SOLUTION: A measurement method for measuring the surface shape of a plane 2 to be measured having the outer shape of a regular hexagon includes a first step for setting a plurality of partial areas 8 having the same outer shape of a parallelogram in the plane 2 to be measured so as to cover the entire plane 2 to be measured, a second step for measuring respective surface shapes of the plurality of partial areas 8 with a measuring instrument, and acquiring measurement data about each of the plurality of partial areas 8, a third step for calculating the surface shape of the plane 2 to be measured by connecting the respective measurement data of the plurality of partial areas 8. The parallelogram has internal angles of 120 and 60 degrees, and the maximum length of one side is equal to or shorter than the length of one side of the regular hexagon.