An optical coherence tomography device includes an SS-OCT optical system which includes a wavelength swept optical source which sweeps an emission wavelength, an optical splitter which splits an interference signal light caused by interference between a measurement light and a reference light into a first interference signal light and a second interference signal light having a phase difference from the first interference signal light, a balance detector which includes a first detector configured to detect the first interference signal light and a second detector configured to detect the second interference signal light, and which processes detection signals from the first and second detectors to perform balance detection, and an optical member which is disposed between the optical splitter and one of the first detector and the second detector to generate a fixed pattern noise by one of the first interference signal light and the second interference signal light.