The invention relates to a device for Moire measurement of an 
optical test specimen, comprising a 
grating arrangement composed of a first 
grating (25, 25', 35, 35'), which is positionable in the 
optical beam path upstream of the test specimen, and a second 
grating (11, 11', 11", 41, 51, 61, 71, 81, 91, 101, 111, 121, 131, 141), which is positionable in the 
optical beam path downstream of the testspecimen, an evaluation unit having at least one 
detector (12, 12', 12", 22, 22', 32, 32', 42, 52, 62, 72, 82, 92, 102, 112, 122, 132, 142) for evaluating Moire structures produced by superimpositionof the two gratings in a detection plane situated in the 
optical beam path downstream of the second grating, and at least one aperture stop (14, 14', 14", 24, 24', 34, 34'), by which the light distribution produced after emergence of light from the second grating can be shaded regionally in such a way that only light of a subset of all field points on the second grating reaches the detection plane.