A laser radar device comprising: a primary light source configured to combine a plurality of laser beams having different wavelengths respectively to generate primary light; an optical splitter configured to split the primary light into transmission light and reference light; an optical modulator configured to modulate the transmission light to generate modulated transmission light; an optical transmitter/receiver system configured to emit the modulated transmission light into an external space and receive light scattered or diffused by a target in the external space; an optical combiner configured to combine the reference light and the light received by the optical transmitter/receiver system to generate an optical beat signal; a photodetector circuit configured to perform an optical-to-electrical signal conversion of the optical beat signal to generate a received signal; and a signal processing circuit including: a frequency analyzer configured to perform frequency analysis on the received signal with a frequency resolution specified in advance to calculate a spectrum of the received signal, where the spectrum is a power spectrum or an amplitude spectrum; and a measurement value calculator configured to calculate a measurement value related to the target, which is a relative velocity of the target, on a basis of the calculated spectrum, characterized in that the different wavelengths are set to cause a frequency difference between peaks that correspond to the different wavelengths and appear in the spectrum of the received signal, to be equal to or less than the frequency resolution; the measurement value calculator is configured to calculate the relative velocity of the target in a predetermined velocity measurement range; and the different wavelengths are set to satisfy a relational expression given by Δ f > 2 × V max × 1 / λ min − 1 / λ max, where a maximum absolute value of a velocity in the velocity measurement range is denoted by V max, a maximum wavelength of the different wavelengths is denoted by λ max, a minimum wavelength of the different wavelengths is denoted by λ min, and the frequency resolution is denoted by Δf. a primary light source configured to combine a plurality of laser beams having different wavelengths respectively to generate primary light; an optical splitter configured to split the primary light into transmission light and reference light; an optical modulator configured to modulate the transmission light to generate modulated transmission light; an optical transmitter/receiver system configured to emit the modulated transmission light into an external space and receive light scattered or diffused by a target in the external space; an optical combiner configured to combine the reference light and the light received by the optical transmitter/receiver system to generate an optical beat signal; a photodetector circuit configured to perform an optical-to-electrical signal conversion of the optical beat signal to generate a received signal; and a signal processing circuit including: a frequency analyzer configured to perform frequency analysis on the received signal with a frequency resolution specified in advance to calculate a spectrum of the received signal, where the spectrum is a power spectrum or an amplitude spectrum; and a measurement value calculator configured to calculate a measurement value related to the target, which is a relative velocity of the target, on a basis of the calculated spectrum, characterized in that a frequency analyzer configured to perform frequency analysis on the received signal with a frequency resolution specified in advance to calculate a spectrum of the received signal, where the spectrum is a power spectrum or an amplitude spectrum; and a measurement value calculator configured to calculate a measurement value related to the target, which is a relative velocity of the target, on a basis of the calculated spectrum, characterized in that the measurement value calculator is configured to calculate the relative velocity of the target in a predetermined velocity measurement range; and the different wavelengths are set to satisfy a relational expression given by Δ f > 2 × V max × 1 / λ min − 1 / λ max, where a maximum absolute value of a velocity in the velocity measurement range is denoted by V max, a maximum wavelength of the different wavelengths is denoted by λ max, a minimum wavelength of the different wavelengths is denoted by λ min, and the frequency resolution is denoted by Δf.