An apparatus is small, capable of accurately obtaining biometric information, and improves authentication accuracy. A blood vessel image capturing apparatus includes a position area on which a finger 1 is placed, a light source 3 configured to irradiate a finger 1 presented on the position area, an imaging unit 9 configured to form an image of light emitted from the light source 3 and transmitted through the finger 1, a pressure detecting unit 23 configured to detect pressure of the finger 1 placed on the position area, and an image processing unit 10 configured to process an image formed by the imaging unit 9. The image processing unit 10 obtains a position of a pressed region 103 where the pressure of the finger 1 is at or more than a predetermined pressure value, calculates similarity between positions of the pressed region 103 and a registered pressed region included in each of previously registered plural images, and selects, according to the calculated similarity, a registered image of the registered plural images to be collated with the image.
