29 b 32 a 32 b of interferometric correction means 29 32 the partial beams 25 a 27 a of beam parts 35 of interferometric measuring means 25 27 which are used for measuring pass from the laser to the mirrored areas 37 38 of positioning stage 18 from where they are reflected as in fig2 only one reflection is shown in fig3 fig4 is a schematic top view of a positioning stage 18 and the optical beam path for determining the positions into which positioning stage 18 can be brought the optical beam path in fig4 is basically comparable to the optical beam path in fig3 however the interferometric correction means 29 32 are incorporated into the interferometric measuring means 25 27 in fig4 in each case they are implemented as a biaxial interferometer as a result beam splitters 30 33 and the two individual interferometers 29 32 as indicated in fig3 can be advantageously omitted it is therefore no longer necessary to adjust these components during the manufacture of the coordinate measuring device fig5 is a schematic top view of an exemplary embodiment of a measuring apparatus 39 according to the present invention which has an interferometric measuring means and an interferometric correction means therefore the interferometric correction means is incorporated into the interferometric measuring means in the form of a biaxial interferometer laser light 40 coming from a light source not shown in fig5 and entering into measuring device 39 passes through prism.