1. A system for enabling entrance/exit, the system comprising: an input interface for obtaining an image including a personal vein pattern; a personal identification unit for executing a personal identification by generating a vein pattern from the image obtained from the input interface, and comparing the generated vein pattern with a registered vein pattern; a door to be automatically opened in a case that the generated vein pattern is identical with the registered vein pattern; and a control unit for controlling opening/closing of the door, wherein the input interface includes a light source, an imaging device for capturing a light applied from the light source and transmitted through a portion of a human body, and a box having the light source and the imaging device inside thereof, wherein the box has a slot or opening, into which the portion of the human body can be inserted, and wherein the light source and the imaging device are arranged opposite each other with the slot or opening between them.