An arrangement for optical emission spectrometry with a spectrochemical source, which during operation emits non-directed radiation, and with a spectrometer having at least one entry aperture arranged at a side next to the source, at least one dispersive element and at least one detector, which are arranged such that during operation part of the radiation emitted in the direction of the entry aperture from the source enters the spectrometer through the entry aperture, from the entry aperture falls indirectly or directly on the dispersive element(s), is split up according to wavelengths and is registered by the at least one detector. A mirror may be arranged at a side of the source opposed to the entry aperture at a distance from the source to reflect at least one part of the radiation, not emitted in the direction of the entry aperture from the source, in the direction of the entry aperture.