A laser radar device comprising: a spectrum calculating unit for calculating, as signal spectra of a first combined light beam that is a combined light beam of first scattered light of a first laser light beam with a wavelength absorbed by a molecule in an atmosphere scattered by a scattering body in the atmosphere and the first laser light beam, a plurality of first signal spectra in a same time range, and calculating, as signal spectra of a second combined light beam that is a combined light beam of second scattered light of a second laser light beam with a wavelength not absorbed by the molecule scattered by the scattering body and the second laser light beam, a plurality of second signal spectra in the same time range, wherein each of the signal spectra of the first signal spectra in the same time range is spectra of a time range bin of the time range, and each of the signal spectra of the second signal spectra in the same time range is spectra of a time range bin of the time range, wherein the time range is divided into multiple time range bins; a frequency shift correcting unit for correcting a frequency shift of the plurality of first signal spectra with respect to a frequency of the first laser light beam and correcting a frequency shift of the plurality of second signal spectra with respect to a frequency of the second laser light beam; a spectrum integrating unit for integrating the plurality of first signal spectra corrected by the frequency shift correcting unit and integrating the plurality of second signal spectra corrected by the frequency shift correcting unit; and a molecular concentration calculating unit (27; 31) for calculating a concentration of molecules in the atmosphere from the first and second signal spectra integrated by the spectrum integrating unit, wherein the frequency shift correcting unit is configured to perform, before correcting the frequency shift of the first and second signal spectra, a correcting process of selecting any one frequency out of one or more frequencies having a signal component equal to or larger than a threshold in the first and second signal spectra, moving a signal component of the frequency not selected to the selected frequency, and treating a signal component of the selected frequency as a total sum of signal components of the one or more frequencies. a spectrum calculating unit for calculating, as signal spectra of a first combined light beam that is a combined light beam of first scattered light of a first laser light beam with a wavelength absorbed by a molecule in an atmosphere scattered by a scattering body in the atmosphere and the first laser light beam, a plurality of first signal spectra in a same time range, and calculating, as signal spectra of a second combined light beam that is a combined light beam of second scattered light of a second laser light beam with a wavelength not absorbed by the molecule scattered by the scattering body and the second laser light beam, a plurality of second signal spectra in the same time range, wherein each of the signal spectra of the first signal spectra in the same time range is spectra of a time range bin of the time range, and each of the signal spectra of the second signal spectra in the same time range is spectra of a time range bin of the time range, wherein the time range is divided into multiple time range bins; a frequency shift correcting unit for correcting a frequency shift of the plurality of first signal spectra with respect to a frequency of the first laser light beam and correcting a frequency shift of the plurality of second signal spectra with respect to a frequency of the second laser light beam; a spectrum integrating unit for integrating the plurality of first signal spectra corrected by the frequency shift correcting unit and integrating the plurality of second signal spectra corrected by the frequency shift correcting unit; and a molecular concentration calculating unit (27; 31) for calculating a concentration of molecules in the atmosphere from the first and second signal spectra integrated by the spectrum integrating unit, wherein the frequency shift correcting unit is configured to perform, before correcting the frequency shift of the first and second signal spectra, a correcting process of selecting any one frequency out of one or more frequencies having a signal component equal to or larger than a threshold in the first and second signal spectra, moving a signal component of the frequency not selected to the selected frequency, and treating a signal component of the selected frequency as a total sum of signal components of the one or more frequencies.