An optical coherence tomography apparatus includes an OCT optical system configured to detect an OCT signal based on measurement light scanned on scan positions of a subject including a blood vessel network by a scanning unit and reference light. The optical coherence tomography apparatus is configured to execute: a signal processing instruction of processing OCT signals which are temporally different from each other with respect to a same position on the subject and generating a motion contrast image which images distribution of a moving object in a depth direction at each of the scan positions based on the OCT signals; and a detecting instruction of analyzing a profile in the depth direction of the motion contrast image generated by the signal processing unit and detecting a change resulting from the blood vessel to detect the blood vessel network included in the subject.