In order to reduce the time taken for blood flow measurement, the blood flow measurement device according to an embodiment of the present invention includes: a scanning unit for alternately performing first scanning and second scanning for scanning a first cross-section and a second cross-section intersecting with a blood vessel of interest using OCT an image forming unit for forming an image of the first cross-section including a phase image representing the change over time of a phase difference on the basis of data acquired from the first scanning, and forming an image of the second cross-section on the basis of data acquired from the second scanning a blood vessel region specifying unit for specifying a first blood vessel region and a second blood vessel region corresponding to the blood vessel of interest in the image of the first cross-section and the image of the second cross-section, respectively an inclination calculating unit for calculating the inclination of the blood vessel of interest in the first cross-section on the basis of the first blood vessel region and the second blood vessel region and a blood flow information generating unit for generating blood flow information relating to the blood vessel of interest on the basis of the phase image and the inclination of the blood vessel of interest.Linvention vise à réduire le temps requis pour une mesure du débit sanguin, et concerne un débitmètre sanguin, selon une forme de réalisation de la présente invention, qui comprend : une unité de balayage, qui effectue alternativement un premier et un second balayage dune première section transversale et dune seconde section transversale coupant un vaisseau sanguin étudié, au moyen dune TCO (tomographie par cohérence optique) une unité de formation dimage, qui forme une image de la première section transversale comprenant une image de phase représentant le changement dans le temps dune différence de phase sur la base des données acquises par le premier balayage
