Device for interferometric measurement of an object, wherein the device is configured to determine the movement and/or speed of the surface of the object, comprising a radiation source for generating an output beam, a beam splitter device for splitting the output beam into a measuring beam and a reference beam, an optical superimposition device and a first detector, wherein the superimposition device and the first detector are configured to co-operate in such a way that the measuring beam at least partly reflected by the object as received beam and the reference beam are at least partly superimposed on at least one detector surface of the first detector, wherein the beam splitter device is configured to split the output beam into a measuring beam, a first reference sub-beam (5.1) and at least one second reference sub-beam (5.2) and to split the received beam into a first received sub-beam (4.1b) and at least one second received sub-beam (4.2b), wherein the device has at least one second detector and is configured in such a way that the first received sub-beam is superimposed with the first reference sub-beam (5.1) on a detection surface of the first detector and the second received sub-beam (4.2b) is superimposed with the second reference sub-beam (5.2) on a detection surface of the second detector, in each case giving rise to optical interference, characterised in that the device has an evaluating unit for evaluating the measuring signals of the first and second detectors (6, 13), which evaluating unit is configured to evaluate the measuring signals of the two detectors according to the principle of reception diversity in such a way that by means of the two detectors the received beam is evaluated in respect of different criteria and accordingly, at least to some extent, different information contained in the received beam is evaluated by means of the first detector, compared with the information of the received beam evaluated by means of the second detector, wherein the afore-mentioned separation of the information contained in the received beam and assignment on the one hand to the first detector and on the other hand to the second detector is carried out in respect of at least one of the following criteria: - detection of different beam cross-section components, - detection of different modes, - detection of different polarisation components, of the received beam, and the evaluating unit is configured so that both the measuring signal of the first detector and the measuring signal of the second detector is rated in accordance with a quality criterion, there being used for the evaluation that signal which has the higher quality rating or a combined output signal is formed from the measuring signal of the first detector and the measuring signal of the second detector, a weighting being applied on the basis of the quality rating, wherein the quality rating is effected in dependence upon the signal strength of the measuring signal, so that the detector which has a higher signal strength of the measuring signal is given a higher quality rating, compared with the other detector having a lower signal strength of the measuring signal. - detection of different beam cross-section components, - detection of different modes, - detection of different polarisation components,