A spectroscopic measurement device, comprising: a) a transmissive optical phase shifter composed of a first transmissive part having an entrance face and an exit face parallel to each other and a second transmissive part located next to the first transmissive part and shaped like a wedge having an entrance face and an exit face one of which is sloped relative to the other, with either the entrance face or the exit face of the second transmissive part lying on a same plane as either the entrance face or the exit face of the first transmissive part; b) an objective lens for collimating a measurement beam emitted from each of a plurality of measurement points located within a measurement area of an object to be measured and for making the collimated beam enter the first transmissive part and the second transmissive part ; c) a cylindrical lens having an axis parallel to a line of intersection of the entrance face of the first transmissive part and a boundary surface between the first transmissive part and the second transmissive part, for receiving a first measurement beam exiting from the first transmissive part and a second measurement beam exiting from the second transmissive part ; d) a detector including a plurality of pixels and being positioned for detecting an intensity distribution of an interference light produced from the first measurement beam and the second measurement beam entering the cylindrical lens; and e) a processor for acquiring an interferogram of the measurement points of the object to be measured based on the intensity distribution of the interference light detected by the detector, and for Fourier-transforming the interferogram to obtain a spectrum, wherein the transmissive optical phase shifter , the objective lens , the cylindrical lens , and the detector are arranged in a linear form. a) a transmissive optical phase shifter composed of a first transmissive part having an entrance face and an exit face parallel to each other and a second transmissive part located next to the first transmissive part and shaped like a wedge having an entrance face and an exit face one of which is sloped relative to the other, with either the entrance face or the exit face of the second transmissive part lying on a same plane as either the entrance face or the exit face of the first transmissive part; b) an objective lens for collimating a measurement beam emitted from each of a plurality of measurement points located within a measurement area of an object to be measured and for making the collimated beam enter the first transmissive part and the second transmissive part ; c) a cylindrical lens having an axis parallel to a line of intersection of the entrance face of the first transmissive part and a boundary surface between the first transmissive part and the second transmissive part, for receiving a first measurement beam exiting from the first transmissive part and a second measurement beam exiting from the second transmissive part ; d) a detector including a plurality of pixels and being positioned for detecting an intensity distribution of an interference light produced from the first measurement beam and the second measurement beam entering the cylindrical lens; and e) a processor for acquiring an interferogram of the measurement points of the object to be measured based on the intensity distribution of the interference light detected by the detector, and for Fourier-transforming the interferogram to obtain a spectrum, wherein the transmissive optical phase shifter , the objective lens , the cylindrical lens , and the detector are arranged in a linear form. <EOS>