Provided is an OCT device capable of restraining degradation of OCT image quality and cost increase of parts and generating a scan trigger signal. The OCT device of the present invention comprises: a light source for outputting laser light having oscillation wavelength and output power both changing with time an interference optical system, in which first laser light output from the light source is divided, into measurement light and reference light such that the measurement light is output so as to irradiate the object and the reference light is caused to pass through a reference light path, and the measurement light back-scattered from the object and the reference light having passed through the reference light path are combined to be output, the transmissivity of the interference optical system having a wavelength dependence opposite to the wavelength dependence of the first output power of the light source and an OCT photodetector for generating an OCT electrical signal with a value according to interference light intensity by detecting interference light which is a combination of the reference light and the measurement light outputted from the interference optical system.
