1. A personal identification apparatus comprising: a light source which irradiates a finger; an imaging unit which captures a transmitted light from the finger; an image processing unit which extracts a blood vessel pattern from a image captured with the imaging unit, and compares the blood vessel pattern with a registered blood vessel pattern; and a fixing device which doesn't contact a surface from which the transmitted light passed and contacts a part of the finger; wherein the light source comprises light-emitting elements arranged according to the shape of the finger as the capture.