1. A method for aligning three-dimensional shape data obtained by performing a three-dimensional measurement of an object, the method comprising the steps of: providing a target mark on the object; performing photogrammetry of the object to obtain a three-dimensional position and a normal vector of the target mark by a calculation; performing the three-dimensional measurement of the object to obtain a three-dimensional position and a normal vector of the target mark; determining a correspondence between the three-dimensional position of the target mark obtained by the photogrammetry and the three-dimensional position of the target mark obtained by the three-dimensional measurement, by using the three-dimensional position and the normal vector of the target mark obtained by the photogrammetry and the three-dimensional position and the normal vector of the target mark obtained by the three-dimensional measurement; and aligning three-dimensional shape data obtained by the three-dimensional measurement based on the correspondence between the three-dimensional positions of the target marks.