The invention concerns a device for acquiring the three-dimensional shape of an object (10) by opto-electronic process, comprising a chromatic system (18) for illuminating the object (10) and for picking up the light reflected or backscattered by the object (10), and a reflecting mirror (26) placed on the optical axis between the optical system (18) and an illumination slot (16) for deflecting the light reflected by the object towards a spectral analysis means (30).