To provide a laser device capable of executing highly reliable and accurate distance measurement utilizing a self-coupling effect of a laser element regardless of the change of a wavelength changing rate characteristic of the laser element.

Feedback control of a driving condition of the laser element is performed so that a modulated laser light component is kept constant, based on information of the modulated laser light component generated by a self-coupling effect between a wavelength modulated laser light output from the laser element and reflected light from a reference point, set beforehand, of the laser light. For example, a driving current of the laser element is corrected based on a correction coefficient calculated theoretically, or feedback control of an amplitude of the driving current or its period increased and decreased periodically in order to perform wavelength modulation of the laser light is performed.