Method for determining an analyte in a scattering matrix. In a detection step detection measurements are made in which light is irradiated into the matrix as primary light and light leaving the scattering matrix is detected as secondary light, in order to determine as a measurement quantity a measurable physical property of the light which is variable due to the interaction of the light with the matrix. Information on the presence of the analyte in the matrix is determined in an evaluation step. The determination of optically weakly absorbing analytes against a strongly absorbing interference background is improved by the use of two selection methods for the depth selective detection of the secondary light in combination with one another. Primary light is focused by means of a primary light optically focussing element onto a region of focus lying in the matrix at a predetermined measuring depth and the region of focus is imaged by means of a secondary light optically focusing element onto a light entry aperture arranged in the light path of the secondary light to the detector. In addition to this first depth selection by a confocal arrangement, a second depth selection device is used to detect light reflected from a defined measuring depth as secondary light, with the measuring depth coinciding with the depth of focus.