Echelle spectrometer assembly with internal separation of the orders, comprising (a) an Echelle grating for the spectral separation of radiation in a main dispersion direction, (b) a prism as dispersing element for the separation of the orders by means of the spectral separation of the radiation in a lateral dispersion direction forming an angle with the main dispersion direction of the Echelle grating such that a two-dimensional spectrum with a plurality of separated orders is generated, (c) an imaging optical assembly (18, 22, 28, 46) for imaging the radiation entering into the spectrometer assembly through an entrance slit into an image plane, and (d) a detector having a two-dimensional arrangement of a plurality of detector elements in the image plane, and (e) predispersion means for predispersion of radiation in the direction of the lateral dispersion of the dispersing element, characterized in that (f) the predispersion means comprise a predispersing grating, which is arranged along the optical path behind the entrance slit inside the spectrometer assembly and which has a grating line number which is adapted to the dispersion of the prism in such a way that the orders imaged onto the detector appear essentially with even distances; (g) the imaging optical assembly is designed in such a way that the predispersed radiation is imaged into an additional image plane, the image plane being arranged along the optical path between the predispersing element and the Echelle grating, and (h) optical means (20, 68) are provided either in the form of an order filter positioned in the additional image plane or in the form of predispersing means which comprise an additional prism having a roof edge which is positioned in such a way that the prism dispersion runs parallel to the main dispersion direction of the Echelle grating and furthermore, the predispersing means comprise a baffle for suppressing higher orders of the predispersing grating. (a) an Echelle grating for the spectral separation of radiation in a main dispersion direction, (b) a prism as dispersing element for the separation of the orders by means of the spectral separation of the radiation in a lateral dispersion direction forming an angle with the main dispersion direction of the Echelle grating such that a two-dimensional spectrum with a plurality of separated orders is generated, (c) an imaging optical assembly (18, 22, 28, 46) for imaging the radiation entering into the spectrometer assembly through an entrance slit into an image plane, and (d) a detector having a two-dimensional arrangement of a plurality of detector elements in the image plane, and (e) predispersion means for predispersion of radiation in the direction of the lateral dispersion of the dispersing element, characterized in that (f) the predispersion means comprise a predispersing grating, which is arranged along the optical path behind the entrance slit inside the spectrometer assembly and which has a grating line number which is adapted to the dispersion of the prism in such a way that the orders imaged onto the detector appear essentially with even distances; (g) the imaging optical assembly is designed in such a way that the predispersed radiation is imaged into an additional image plane, the image plane being arranged along the optical path between the predispersing element and the Echelle grating, and (h) optical means (20, 68) are provided either in the form of an order filter positioned in the additional image plane or in the form of predispersing means which comprise an additional prism having a roof edge which is positioned in such a way that the prism dispersion runs parallel to the main dispersion direction of the Echelle grating and furthermore, the predispersing means comprise a baffle for suppressing higher orders of the predispersing grating.