PURPOSE: To prevent wrong reading of bar codes so as to read bar codes accurately even when the moving speed of the bar codes is fast by scanning the bar codes by using plural light sources which emit light beams having different identity characteristics and respectively decoding output signals of a photoelectric converting means in accordance with the identity characteristics of the light beams.

CONSTITUTION: Plural light sources 21 and 22 which emit light beams having different identity characteristics, a scanning means 27 which simultaneously deflects the light beams and produces a scanning pattern, and a photoelectric converting means 30 which receives reflecting light obtained from the bar code scanning of the scanning pattern and makes photoelectric conversion on the reflecting light are provided. In addition, plural decoder circuits 31 and 32 which decode the output signal of the means 30 in accordance with the identity characteristics of the light beams from the light sources 21 and 22 and discriminating means 33 and 34 which compare decoded data with each other and discriminate the validity of the data are also provided. Therefore, wrong reading of bar codes can be prevented surely and, in addition, the bar codes can be read surely even when the moving speed of the bar codes is fast.