A non-invasive blood analyzer includes a light source unit for irradiating a portion of a living body, the portion including a blood vessel, and includes an image capturing unit for capturing an image of the irradiated portion. An analyzing unit is included for setting an analysis region in the captured image and analyzing a blood vessel portion in the set analysis region. The image capturing unit captures images of the irradiated portion of the living body a plurality of times and the analyzing unit specifies analysis regions including the same blood vessel portions with respect to the captured images. The analyzing unit determines these regions based upon a position of a feature in sequential images and calculates at least one of blood vessel width, blood component concentration and blood component concentration ratio with respect to the blood vessel portion in each specified analysis region.