A spectrometer 1A is made up of: an optical body 10 within which a light separation path is set along which an object light to be separated propagates; a light entry slit 16 through which the object light enters; a diffraction grating 17 for spectrally separating the incident object light; and a photodiode array 18 for detecting the object light separated by the diffraction grating 17. As an optical member for optically interconnecting the optical body 10 and the photodiode array 18, an optical connection member 20 is provided, with its light entry surface 21 for the separated object light in contact with the upper surface 11 of the optical body 10, with its light exit surface 22 in contact with the photodiode array 18, with the light exit surface 22 tilted by a specified angle relative to the light entry surface 21. Thus, the spectrometer capable of bringing about sufficient accuracy of placing optical elements in a simple constitution while bringing down cost is realized.