Provided is an optical device capable of suppressing variations in the range for scanning light. This optical device comprises: a light source that emits a laser beam; a MEMS mirror that scans the laser beam toward a predetermined range; and a diffraction grating that guides the laser beam to the MEMS mirror by guiding the laser beam in a direction corresponding to the wavelength thereof. The optical device also comprises an MEMS control unit that performs control such that, by employing a change in the optical path of the laser beam caused through the diffraction grating by a change in the wavelength of the laser beam, variations in the scanning range of the laser beam by the MEMS mirror are suppressed.