A spectral characteristic obtaining apparatus comprising: a spectroscopic unit configured to separate reflected light from light emitted onto a reading object by a light irradiation unit into a spectrum; and a light receiving unit, including a plurality of spectroscopic sensors (15a, 15b), each of the spectroscopic sensors (15a, 15b) including a plurality of pixels arranged in a direction to receive lights with different spectral characteristics from each other, configured to receive the reflected light separated into the spectrum by the spectroscopic unit and to obtain a spectral characteristic, wherein the spectroscopic unit includes: a hole array including plural holes arranged in a line in a light shielding member; a lens array including a plurality of lenses, each lens being positioned between light shielding walls of the light shielding member and associated with a respective hole of the hole array so as to form an image onto the light receiving unit from the reflected light having passed through each of the plurality of holes of the hole array and a diffraction unit positioned in the light shielding member between the lens array and the light receiving unit configured to lead the lights with different wavelength characteristics to the plurality of pixels, wherein the light shielding member is configured to block unnecessary light and the light shielding walls of the light shielding member are provided between adjacent spectroscopic sensors (15a, 15b), characterized in that the center of each of the plurality of holes of the hole array does not coincide with the center axis of the respective associated lens of the plurality of lenses of the lens array such that zero-order diffraction light hits a light shielding wall of the light shielding member and the light receiving unit and the diffraction unit are arranged such that desired positive first order diffraction light enters the plurality of pixels but undesired diffraction light including zero order diffraction light, negative order diffraction light, or second or higher order diffraction light hardly enters the plurality of pixels. a hole array including plural holes arranged in a line in a light shielding member; a lens array including a plurality of lenses, each lens being positioned between light shielding walls of the light shielding member and associated with a respective hole of the hole array so as to form an image onto the light receiving unit from the reflected light having passed through each of the plurality of holes of the hole array and a diffraction unit positioned in the light shielding member between the lens array and the light receiving unit configured to lead the lights with different wavelength characteristics to the plurality of pixels, wherein the light shielding member is configured to block unnecessary light and the light shielding walls of the light shielding member are provided between adjacent spectroscopic sensors (15a, 15b), characterized in that the center of each of the plurality of holes of the hole array does not coincide with the center axis of the respective associated lens of the plurality of lenses of the lens array such that zero-order diffraction light hits a light shielding wall of the light shielding member and the light receiving unit and the diffraction unit are arranged such that desired positive first order diffraction light enters the plurality of pixels but undesired diffraction light including zero order diffraction light, negative order diffraction light, or second or higher order diffraction light hardly enters the plurality of pixels.