An apparatus and a method for personal identification include an image
pickup section for picking up an image of a blood vessel pattern of a
wrist, a storage unit for storing in advance an image of a blood vessel
pattern of a certain person as a registered image, and a control section
(CPU) for the computation of degrees of similarity according to data
differences between the image of the blood vessel pattern picked up by
the image pickup section and the registered image to determine
identification according to the relationship between the computed degrees
of similarity and a threshold, thereby eliminating the need to carry out
processing by a characteristic extraction section or the like.