We have developed a super compact optical fluorescence spectrometer. Our innovative design combines advantages of guided wave planar optics and free-space microoptics. This innovation allows for miniaturization that is not achievable with pure planar or pure free-space optics. A prototype device has volume of its optical part below 1cm. The spectrometer covers 450nm-650nm spectral range, and provides spectral resolution of 0.5nm. Next generation prototype, currently under development, will have volume below 10mm, cover the entire visible range from 400-700nm, provide spectral resolution of at least 2nm, and work simultaneously with up to 35 independent optical inputs. The key component of the microspectrometer is diffractive optical element. The targeted application is on-chip diagnostic systems, in particular for detection of hazardous materials.