Abstract: The spectroscopic analysis device (1) includes an imaging section (70), an optical scanning section, and an analyzing section (80). The imaging section (70) is capable of imaging a plurality of molecules (26), which are contained in a sample (25), at a single-molecule level. The optical scanning section is capable of relatively moving a conjugate plane (72) of an imaging plane (71) of the imaging section (70) to scan the sample (25). The analyzing section (80) is capable of obtaining a concentration of the plurality of molecules (26) by analyzing an image of the plurality of molecules (26) which image has been obtained by the imaging section (70). Therefore, it is possible to accurately measure, by using the spectroscopic analysis device (1), the concentration of the plurality of molecules (26) which are thinly distributed in the sample (25) having a relatively large volume.