An optical coherence tomography device includes an OCT optical system that irradiates a tissue of the subject's eye with measurement light from a light source, and detects interference between reference light and the measurement light reflected from the tissue by using a detector, and a processor, in which the processor performs a generation process of acquiring A-scan data based on a signal output from the detector in a cycle of 300 kilohertz or more and generating three-dimensional OCT data at any time based on the acquired A-scan data, and performs an analysis process on each piece of the three-dimensional OCT data generated at any time through the generation process, so as to output a real-time analysis result of the three-dimensional OCT data which is generated at any time.