An optical coherence tomography apparatus includes: a scanning unit configured to scan a test substance with measurement light; an OCT optical system configured to detect an A scan signal caused by interference between the measurement light and reference light corresponding to the measurement light; and a processor configured to: acquire three-dimensional OCT data in which the A scan signals at respective scanning positions at the test substance are arranged in a two-dimensional manner; acquire a histogram of the A scan signals at the respective scanning positions; and generate an OCT front image by processing the acquired three-dimensional OCT data based on the acquired histogram.