An analysis device for analysing a transparent or specular surface of a substrate, the device including a raster located opposite the surface of the substrate to be measured, a video camera for capturing at least one image of the raster deformed by the measured substrate, a raster lighting system, and an image-processing and digital analysis mechanism connected to the video camera. The video camera is a matrix array camera, the raster is provided on a substrate having an oblong shape and is bidirectional including a first pattern extending along a first direction and along a smallest extension of the substrate, the first pattern being transversely periodical to the smallest extension, and a second pattern extending in a second direction perpendicular to the first pattern and along a largest extension of the substrate.