An optical coherence tomography device, - comprising: - an OCT optical system configured to detect measurement light irradiated onto a specimen (Ef, E) and reference light and to output OCT signals based on the measurement light and the reference light; and - an analysis processing unit configured to process the OCT signals and to generate functional OCT data of the specimen (Ef, E), - wherein the analysis processing unit comprises: - a first image data generation unit configured to generate first functional OCT image data by applying first analysis processing on a plurality of OCT signals obtained at different timings for the same position on the specimen (Ef, E); and - a second image data generation unit configured to generate second functional OCT image data by applying second analysis processing that is different from the first analysis processing on a plurality of OCT signals obtained at different timings for the same position on the specimen (Ef, E); - wherein the analysis processing unit is configured to generate the functional OCT image data based on the first functional OCT image data generated by the first image data generation unit and the second functional OCT image data generated by the second image data generation unit, - wherein the first functional image data are based on a phase difference of complex OCT signals, - wherein the second functional OCT image data are based on a vector difference ofecomplex OCT signals, and - wherein the analysis processing unit is configured to apply, to one of the first functional image data and the second functional image data, a mask based on the other one of the first functional image data and the second functional image data in order to remove an artifact at a detected high reflection portion. - comprising: - an OCT optical system configured to detect measurement light irradiated onto a specimen (Ef, E) and reference light and to output OCT signals based on the measurement light and the reference light; and - an analysis processing unit configured to process the OCT signals and to generate functional OCT data of the specimen (Ef, E), - wherein the analysis processing unit comprises: - a first image data generation unit configured to generate first functional OCT image data by applying first analysis processing on a plurality of OCT signals obtained at different timings for the same position on the specimen (Ef, E); and - a second image data generation unit configured to generate second functional OCT image data by applying second analysis processing that is different from the first analysis processing on a plurality of OCT signals obtained at different timings for the same position on the specimen (Ef, E); - wherein the analysis processing unit is configured to generate the functional OCT image data based on the first functional OCT image data generated by the first image data generation unit and the second functional OCT image data generated by the second image data generation unit, - wherein the first functional image data are based on a phase difference of complex OCT signals, - wherein the second functional OCT image data are based on a vector difference ofecomplex OCT signals, and - wherein the analysis processing unit is configured to apply, to one of the first functional image data and the second functional image data, a mask based on the other one of the first functional image data and the second functional image data in order to remove an artifact at a detected high reflection portion.