Provided is a small-sized, flat, vein authentication device of high authentication accuracy by photographing a living body several times and thus obtaining as registration data plural images that are picked up at different positions. A biometric information processing device of this invention comprising an image pickup device, which picks up a vein image, an image computing unit, which processes the vein image picked up by the image pickup device, an interface on which a part of a living body to be picked up is placed, and a light source, which emits infrared light. The biometric information processing device is further comprised of a sensor unit, which detects the presence or absence of a subject picked up by the image pickup device, a unit to obtain plural images as registration data, and a unit to select optimum registration data out of images obtained as registration data.本發明之目的在於提供一種小型平面的靜脈認證裝置,且為了吸收生物體出示時產生之位置偏移,藉由多次之生物體之出示獲得相互拍攝位置不同的多個註冊資料,從而認證精度較高。本發明的靜脈認證裝置,包含拍攝靜脈圖像的拍攝部、處理藉由上述拍攝部所拍攝之靜脈圖像的圖像運算部、承載所拍攝之生物體的介面、及發射紅外光的光源,其特徵在於包括:判斷藉由上述拍攝部所拍攝之被寫體之有無的被寫體檢測部、獲得多個註冊資料之機構、及自多個註冊資料選擇最合適的註冊資料之機構。1‧‧‧手指23‧‧‧光源25‧‧‧手指放置面27‧‧‧開口部31,37‧‧‧壓克力板33‧‧‧傾斜部35‧‧‧光照射口39‧‧‧關節位置規定記號41‧‧‧手指放置位置記號43‧‧‧導向用燈
