An optical analysis device for determining particulate matter includes three light sources having different wavelengths, an apparatus for combining the three transmitted light beams on a common optical path, a measurement volume, an optical axis in the forward scattering direction defines the scattering angle 0°, a light absorption apparatus at 0° that absorbs unscattered light, and six detectors which are arranged at different specified angles which are as close as possible to 0° directly next to the light absorption apparatus, at a second scattering angle between 7° and 40°, at a third scattering angle between 41° and 70°, at a fourth scattering angle between 71° and 115°, at a fifth scattering angle between 116° and 145°, at a sixth scattering angle between 146° and 180°. A control and evaluation unit controls the light sources such that the scattered light is detected in a wavelength selective manner by the detectors.