PURPOSE: To provide a method and device for specifying geometrical shape combination elements in a coordinate measuring machine where an operation can be completed easily and quickly and at the same time the selection mistake of two symmetrical lines and symmetrical surfaces cannot occur easily when obtaining the geometrical shape combination elements of a measured work.

CONSTITUTION: After a worker selects at least two measurement positions of a work with a coordinate measuring instrument, the geometrical shape of the measured measurement position is calculated and stored (61), a probe is moved closer to geometrical shape combination elements obtained by the worker for setting the probe position (62) and at the same time the calculation and selection of the geometrical shape combination elements are instructed (63). Two geometrical shapes, namely the most recently stored geometrical shape and a geometrical shape stored immediately before, out of the stored geometrical shapes, are called (64), the combination elements of two geometrical shapes are calculated and at the same time combination elements closest to the set probe position are selected (65) and are outputted (66).