An optical member capable of detecting a high-contrast and clear uneven image. The optical member (2A) is in contact with the surface of the finger, which is an object, and has an incident surface (2a) on which the light from the finger surface is incident and an emission surface (on which the light incident on the incident surface (2a) is emitted. 2b), and a refraction layer (3) is formed between the exit surface (2b) and the image sensor, and the incident surface (2a) of the light incident on the entrance surface (2a). The light emitted into the optical member (2A) at an angle inclined with respect to the normal (L1) direction of is propagated to the emission surface (2b), and the light is provided between the emission surface 2b and the image sensor 4A. The light is refracted so as to approach the normal direction of the image pickup element (4A) by being emitted to the image pickup element (4A) through the refraction layer 3.高コントラストかつ鮮明な凹凸像を検出することが可能な光学部材を提供する。 光学部材（２Ａ）は、対象物である指の表面と接触し、指の表面からの光が入射する入射面（２ａ）と、入射面（２ａ）に入射した光が出射される出射面（２ｂ）と、を有し、出射面（２ｂ）と撮像素子との間には、屈折層（３）が構成されており、入射面（２ａ）に入射する光のうち、入射面（２ａ）の法線（Ｌ１）方向に対して傾斜する角度で光学部材（２Ａ）内に出射する光を出射面（２ｂ）まで伝搬し、光を出射面２ｂと撮像素子４Ａとの間に設けられた屈折層３を介して撮像素子（４Ａ）へ出射することによって、光を撮像素子（４Ａ）の法線方向に近づくように屈折させる。
