An optical tomographic image photographing apparatus for acquiring information on a tissue inside a specimen, the apparatus includes: a synthesis unit configured to generate a interference beam by synthesizing a measuring beam reflected from the tissue and a reference beam; and a detector configured to detect the generated first interference beam as a first interference signal, the first interference beam being detected for each scanning position of the measuring beam. The optical tomographic image photographing apparatus acquires tomographic information for each scanning position of the specimen by using the detected first interference signal and acquiring tomographic image data of the specimen expressed by polar coordinates by using the tomographic information; and converts the tomographic image data of the specimen expressed by the acquired polar coordinates into image data expressed by rectangular coordinates.