PURPOSE: To obtain an image reader in which the effect of mirror surface reflection is reduced.

CONSTITUTION: A plurality of lighting light sources 44 emit lights to an object 45. A 1st polarized light filter 58 receives the non-polarized light from the light sources and passes only the lights polarized in a 1st direction. The light reflected from the object is returned to the reader. Then, the light is received by a 2nd polarizer 59 that is directed to shut the light polarized in the 1st direction and to pass only the light polarized in a 2nd direction orthogonal to the 1st polarized light direction. The non-mirror surface reflected light reflected from the object mainly passed through a detector assembly 48 in the image reader by the 2nd polarizer 59. In a mode, the polarization filter being a part of a window covering an output opening of the polarization filter and the reader is put into practice as separate segments of a thin layer polarization film adhered to a transparent window base 52.